0001423689-21-000063 | 10-Q | XBRL Viewer

Fair Value Measurements

6 Months Ended

Jun. 30, 2021

The following table provides a summary of our assets and liabilities that are measured at fair value on a recurring basis, as of June 30, 2021 and December 31, 2020, based on their categorization within the valuation hierarchy (in millions). There were no transfers between valuation hierarchy levels during the periods presented in our accompanying consolidated statements of comprehensive income.


	June 30, 2021						December 31, 2020
	Level 1		Level 2		Level 3		Level 1		Level 2		Level 3
Assets:
Agency securities	$	—	$	57,896	$	—	$	—	$	64,836	$	—
Agency securities transferred to consolidated VIEs	—		245		—		—		295		—
Credit risk transfer securities	—		1,105		—		—		737		—
Non-Agency securities	—		553		—		—		546		—
U.S. Treasury securities	397		—		—		—		—		—
Interest rate swaps	—		—		—		—		—		—
Swaptions	—		294		—		—		116		—
TBA securities	—		87		—		—		275		—

Total	$	397	$	60,180	$	—	$	—	$	66,805	$	—
Liabilities:
Debt of consolidated VIEs	$	—	$	148	$	—	$	—	$	177	$	—
Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements	10,920		—		—		11,727		—		—
Interest rate swaps	—		—		—		—		—		—
TBA securities	—		8		—		—		—		—
U.S. Treasury futures	6		—		—		2		—		—
Total	$	10,926	$	156	$	—	$	11,729	$	177	$	—

Excluded from the table above are financial instruments presented in our consolidated financial statements at cost. The fair value of our repurchase agreements approximated cost as of June 30, 2021 and December 31, 2020, as the rates on our outstanding repurchase agreements largely corresponded to prevailing rates observed in the repo market. The fair value of cash and cash equivalents, restricted cash, receivables and other payables were determined to approximate cost as of June 30, 2021 and December 31, 2020 due to their short duration. We estimate the fair value of these instruments carried at cost using "Level 1" or "Level 2" inputs.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Stockholders' Equity (At-the-Market Offering Program) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Value, New Issues	$ 439

Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2021

Equity [Abstract]

Preferred Stock [Table Text Block]


Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock 1	Issuance Date	Depositary Shares Issued and Outstanding	Carrying Value		Aggregate Liquidation Preference		Fixed Rate	Optional Redemption Date 2	Fixed-to-Floating Rate Conversion Date	Floating Annual Rate
Series C	August 22, 2017	13.0	315		325		7.000%	October 15, 2022	October 15, 2022	3M LIBOR + 5.111%
Series D	March 6, 2019	9.4	227		235		6.875%	April 15, 2024	April 15, 2024	3M LIBOR + 4.332%
Series E	October 3, 2019	16.1	390		403		6.500%	October 15, 2024	October 15, 2024	3M LIBOR + 4.993%
Series F	February 11, 2020	23.0	557		575		6.125%	April 15, 2025	April 15, 2025	3M LIBOR + 4.697%
Total		61.5	$	1,489	$	1,538

________________________________

Schedule of Accumulated Other Comprehensive Income (Loss)

The following table summarizes changes to accumulated OCI for the three and six months ended June 30, 2021 and 2020 (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
Accumulated Other Comprehensive Income (Loss)	2021		2020		2021		2020
Beginning Balance	$	482	$	561	$	719	$	97
OCI before reclassifications	(63)		242		(282)		707
Net loss amounts for available-for-sale securities reclassified from accumulated OCI to realized gain (loss) on sale of investment securities, net	(14)		(39)		(32)		(40)
Ending Balance	$	405	$	764	$	405	$	764

Organization (Details)	6 Months Ended
Organization (Details)	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Required Annual Distribution of Taxable Net Income	90.00%
Intended annual distribution of taxable net income	100.00%

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Statement of Cash Flows [Abstract]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 1,570,000	$ 2,165,000
Operating activities:
Net income (loss)	564,000	(1,703,000)
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of premiums and discounts on mortgage-backed securities, net	128,000	607,000
Stock based compensation	8,000	7,000
Gain on sale of investment securities, net	(12,000)	(647,000)
Unrealized (gain) loss on investment securities measured at fair value through net income, net	983,000	(876,000)
(Gain) loss on derivative instruments and other securities, net	(821,000)	3,539,000
(Increase) decrease in other assets	(52,000)	59,000
Decrease in accounts payable and other accrued liabilities	(27,000)	(210,000)
Net cash provided by operating activities	771,000	776,000
Investing activities:
Purchases of Agency mortgage-backed securities	(23,954,000)	(39,715,000)
Purchases of credit risk transfer and non-Agency securities	(1,310,000)	(396,000)
Proceeds from sale of Agency mortgage-backed securities	18,311,000	54,967,000
Proceeds from sale of credit risk transfer and non-Agency securities	931,000	536,000
Principal collections on Agency mortgage-backed securities	8,791,000	7,867,000
Principal collections on credit risk transfer and non-Agency securities	36,000	49,000
Payments on U.S. Treasury securities	(10,536,000)	(19,793,000)
Proceeds from U.S. Treasury securities	10,172,000	16,206,000
Net proceeds from (payments on) reverse repurchase agreements	(233,000)	2,270,000
Net proceeds from (payments on) derivative instruments	593,000	(2,682,000)
Net cash provided by investing activities	2,801,000	19,309,000
Financing activities:
Proceeds from repurchase arrangements	1,163,175,000	2,166,205,000
Payments on repurchase agreements	(1,166,804,000)	(2,185,702,000)
Payments on debt of consolidated variable interest entities	(26,000)	(29,000)
Net proceeds from preferred stock issuance	0	(557,000)
Net proceeds from common stock issuance	0	439,000
Payments for common stock repurchases	(239,000)	(147,000)
Cash dividends paid	(432,000)	(525,000)
Net cash provided used in financing activities	(4,326,000)	(19,202,000)
Net change in cash and cash equivalents	(754,000)	$ 883,000
Cash and cash equivalents at end of period	$ 947,000

Investment Securities

6 Months Ended

Jun. 30, 2021

Investments, Debt and Equity Securities [Abstract]

Investment Securities

As of June 30, 2021 and December 31, 2020, our investment portfolio consisted of: $59.8 billion and $66.4 billion investment securities, at fair value, respectively; $27.4 billion and $31.5 billion net TBA securities, at fair value, respectively; and $0.3 billion and zero forward settling non-Agency securities, at fair value, respectively. Our net TBA position and forward settling non-Agency securities are reported at their net carrying value totaling $79 million and $275 million as of June 30, 2021 and December 31, 2020, respectively, in derivative assets / (liabilities) on our accompanying consolidated balance sheets. The net carrying value of our TBA position and forward settling non-Agency securities represents the difference between the fair value of the underlying security and the cost basis or the forward price to be paid or received for the underlying security.

As of June 30, 2021 and December 31, 2020, our investment securities had a net unamortized premium balance of $2.1 billion and $2.4 billion, respectively.

The following tables summarize our investment securities as of June 30, 2021 and December 31, 2020, excluding TBA and forward settling securities, (dollars in millions). Details of our TBA and forward settling securities as of each of the respective dates are included in Note 5.


	June 30, 2021				December 31, 2020
Investment Securities	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Agency RMBS:
Fixed rate	$	56,418	$	57,757	$	61,977	$	64,615
Adjustable rate	54		56		69		70
CMO	219		228		289		301
Interest-only and principal-only strips	84		100		105		126
Multifamily	—		—		17		19
Total Agency RMBS	56,775		58,141		62,457		65,131
Non-Agency RMBS	187		200		178		188
CMBS	336		353		333		358
CRT securities	1,081		1,105		733		737
Total investment securities	$	58,379	$	59,799	$	63,701	$	66,414


	June 30, 2021
	Agency RMBS									Non-Agency
Investment Securities	Fannie Mae			Freddie Mac			Ginnie Mae			RMBS			CMBS			CRT			Total
Available-for-sale securities:
Par value	$	7,615		$	2,538		$	2		$	—		$	—		$	—		$	10,155
Unamortized discount	(3)			(1)			—			—			—			—			(4)
Unamortized premium	367			127			—			—			—			—			494
Amortized cost	7,979			2,664			2			—			—			—			10,645
Gross unrealized gains	310			95			—			—			—			—			405
Gross unrealized losses	—			—			—			—			—			—			—
Total available-for-sale securities, at fair value	8,289			2,759			2			—			—			—			11,050
Securities remeasured at fair value through earnings:
Par value	30,548			13,992			3			196			338			1,077			46,154
Unamortized discount	(15)			(3)			—			(12)			(6)			(9)			(45)
Unamortized premium	1,070			535			—			3			4			13			1,625
Amortized cost	31,603			14,524			3			187			336			1,081			47,734
Gross unrealized gains	759			362			—			13			18			26			1,178
Gross unrealized losses	(109)			(51)			—			—			(1)			(2)			(163)
Total securities remeasured at fair value through earnings	32,253			14,835			3			200			353			1,105			48,749
Total securities, at fair value	$	40,542		$	17,594		$	5		$	200		$	353		$	1,105		$	59,799
Weighted average coupon as of June 30, 2021	3.15		%	3.23		%	4.73		%	4.23		%	3.69		%	3.58		%	3.19		%
Weighted average yield as of June 30, 2021 1	2.37		%	2.38		%	2.56		%	4.38		%	4.01		%	4.09		%	2.42		%

________________________________

1.Incorporates a weighted average future constant prepayment rate assumption of 11.6% based on forward rates as of June 30, 2021.


	December 31, 2020
	Agency RMBS									Non-Agency
Investment Securities	Fannie Mae			Freddie Mac			Ginnie Mae			RMBS			CMBS			CRT			Total
Available-for-sale securities:
Par value	$	9,325		$	3,416		$	2		$	—		$	—		$	—		$	12,743
Unamortized discount	(4)			(1)			—			—			—			—			(5)
Unamortized premium	389			152			—			—			—			—			541
Amortized cost	9,710			3,567			2			—			—			—			13,279
Gross unrealized gains	539			180			—			—			—			—			719
Gross unrealized losses	—			—			—			—			—			—			—
Total available-for-sale securities, at fair value	10,249			3,747			2			—			—			—			13,998
Securities remeasured at fair value through earnings:
Par value	32,824			14,447			3			187			331			735			48,527
Unamortized discount	(18)			(1)			—			(12)			(3)			(12)			(46)
Unamortized premium	1,314			607			—			4			6			10			1,941
Amortized cost	34,120			15,053			3			179			334			733			50,422
Gross unrealized gains	1,280			683			—			11			28			12			2,014
Gross unrealized losses	(5)			(1)			—			(2)			(4)			(8)			(20)
Total securities remeasured at fair value through earnings	35,395			15,735			3			188			358			737			52,416
Total securities, at fair value	$	45,644		$	19,482		$	5		$	188		$	358		$	737		$	66,414
Weighted average coupon as of December 31, 2020	3.30		%	3.56		%	4.73		%	4.28		%	4.13		%	3.43		%	3.39		%
Weighted average yield as of December 31, 2020 1	2.25		%	2.39		%	2.46		%	4.33		%	4.29		%	3.71		%	2.33		%

________________________________

1.Incorporates a weighted average future constant prepayment rate assumption of 17.6% based on forward rates as of December 31, 2020.

As of June 30, 2021 and December 31, 2020, our investments in CRT and non-Agency securities had the following credit ratings (in millions):


	June 30, 2021						December 31, 2020
CRT and Non-Agency Security Credit Ratings 1	CRT		RMBS		CMBS		CRT		RMBS		CMBS
AAA	$	—	$	—	$	21	$	—	$	—	$	35
AA	—		20		118		—		20		190
A	—		36		39		—		32		28
BBB	72		77		50		28		83		55
BB	222		42		89		167		36		43
B	386		10		36		304		6		7
Not Rated	425		15		—		238		11		—
Total	$	1,105	$	200	$	353	$	737	$	188	$	358

________________________________

1.Represents the lowest of Standard and Poor's ("S&P"), Moody's, Fitch, DBRS, Kroll Bond Rating Agency ("KBRA") and Morningstar credit ratings, stated in terms of the S&P equivalent rating as of each date.

Our CRT securities reference the performance of loans underlying Agency RMBS issued by Fannie Mae or Freddie Mac, which were subject to their underwriting standards.

The actual maturities of our investment securities are generally shorter than their stated contractual maturities. The actual maturities of our Agency and high credit quality non-Agency RMBS are primarily affected by principal prepayments and to a lesser degree the contractual lives of the underlying mortgages and periodic contractual principal repayments. The actual maturities of our credit-oriented investments are primarily impacted by their contractual lives and default and loss recovery rates. As of June 30, 2021 and December 31, 2020, the weighted average expected constant prepayment rate ("CPR") over the remaining life of our Agency and high credit quality non-Agency RMBS investment portfolio was 11.6% and 17.6%, respectively. Our estimates can differ materially for different securities and thus our individual holdings have a wide range of projected CPRs. The following table summarizes our investments as of June 30, 2021 and December 31, 2020 according to their estimated weighted average life classification (dollars in millions):


	June 30, 2021						December 31, 2020
Estimated Weighted Average Life of Investment Securities	Fair Value		Amortized Cost		Weighted Average Coupon	Weighted Average Yield	Fair Value		Amortized Cost		Weighted Average Coupon	Weighted Average Yield
≤ 3 years	$	1,407	$	1,370	3.59%	2.69%	$	3,642	$	3,569	3.56%	2.15%
> 3 years and ≤ 5 years	15,366		14,905		3.62%	2.49%	47,740		45,578		3.54%	2.42%
> 5 years and ≤10 years	40,176		39,276		3.07%	2.41%	15,019		14,541		2.87%	2.08%
> 10 years	2,850		2,828		2.32%	2.09%	13		13		5.56%	3.59%
Total	$	59,799	$	58,379	3.19%	2.42%	$	66,414	$	63,701	3.39%	2.33%

Gains and Losses on Sale of Investment Securities

The following table is a summary of our net gain (loss) from the sale of investment securities for the three and six months ended June 30, 2021 and 2020 by investment classification of accounting (in millions):


	Three Months Ended June 30,
	2021						2020
Investment Securities	Available-for-Sale Securities 2		Fair Value Option Securities		Total		Available-for-Sale Securities 2		Fair Value Option Securities		Total
Investment securities sold, at cost	$	(4,151)	$	(8,659)	$	(12,810)	$	(1,278)	$	(4,472)	$	(5,750)
Proceeds from investment securities sold 1	4,165		8,670		12,835		1,317		4,586		5,903
Net gain (loss) on sale of investment securities	$	14	$	11	$	25	$	39	$	114	$	153

Gross gain on sale of investment securities	$	14	$	48	$	62	$	39	$	129	$	168
Gross loss on sale of investment securities	—		(37)		(37)		—		(15)		(15)
Net gain (loss) on sale of investment securities	$	14	$	11	$	25	$	39	$	114	$	153


	Six Months Ended June 30,
	2021						2020
Investment Securities	Available-for-Sale Securities 2		Fair Value Option Securities		Total		Available-for-Sale Securities 2		Fair Value Option Securities		Total
Investment securities sold, at cost	$	(4,644)	$	(14,523)	$	(19,167)	$	(1,433)	$	(53,912)	$	(55,345)
Proceeds from investment securities sold 1	4,676		14,503		19,179		1,473		54,519		55,992
Net gain (loss) on sale of investment securities	$	32	$	(20)	$	12	$	40	$	607	$	647

Gross gain on sale of investment securities	$	32	$	97	$	129	$	40	$	696	$	736
Gross loss on sale of investment securities	—		(117)		(117)		—		(89)		(89)
Net gain (loss) on sale of investment securities	$	32	$	(20)	$	12	$	40	$	607	$	647

________________________________

1.Proceeds include cash received during the period, plus receivable for investment securities sold during the period as of period end.

2.See Note 9 for a summary of changes in accumulated OCI.

Pledged Assets (Narrative) (Details)	Jun. 30, 2021
Pledged Assets [Abstract]
Risk Of Repurchase Agreement To Stockholders Equity	2.00%

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 50,319,000	$ 54,314,000
Preferred Stock, Liquidation Preference, Value	1,538,000	$ 1,538,000
Preferred Stock C, Liquidation Preference, Value	325,000
Preferred Stock D, Liquidation Preference, Value	$ 235,000
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	1,500,000	1,500,000
Common Stock, Shares, Issued	524,900	539,500
Common Stock, Shares, Outstanding	524,900	539,500
Common Stock [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Depository shares each representing a 1/1,000th interest in a share of 7.000% Series C Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Title of 12(b) Security	Depositary shares of 7.000% Series C Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Depository shares each representing a 1/1,000th interest in a share of 6.875% Series D Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Title of 12(b) Security	Depositary shares of 6.875% Series D Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Depository shares each representing a 1/1000th interest in a share of 6.500% Series E Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Title of 12(b) Security	Depositary shares of 6.50% Series E Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Depositary shares each representing a 1/1000th interest in a share of 6.125% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Title of 12(b) Security	Depositary shares of 6.125% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Agency Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 49,686,000	$ 53,698,000
Credit Risk Transfer Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	502,000	455,000
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	377,000	458,000
US Treasury Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	1,005,000
Receivable for securities sold [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	147,000	207,000
Asset Pledged as Collateral [Member] \| Credit Risk Transfer Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	502,000	455,000
Asset Pledged as Collateral [Member] \| US Treasury Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 397,000	$ 0

Investment Securities (Components Of Investment Securities) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Schedule of Investments [Line Items]
Debt Securities, Trading		$ 48,749	$ 52,416
Debt Securities, Trading and Available-for-sale		59,799	66,414
Amortized cost		$ 58,379	$ 63,701
Weighted average coupon		3.19%	3.39%
Weighted average yield		2.42%	2.33%
Future Prepayment Rate Assumption Of Investment Portfolio	17.60%	11.60%
Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 10,155	$ 12,743
Unamortized discount		(4)	(5)
Unamortized premium		494	541
Amortized cost		10,645	13,279
Gross unrealized gains		405	719
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		11,050	13,998
Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount		(45)	(46)
Unamortized premium		1,625	1,941
Debt Securities, Trading, Unrealized Gain		1,178	2,014
Debt Securities, Trading, Unrealized Loss		(163)	(20)
Trading Securities, Cost		47,734	50,422
Trading Securities Par		46,154	48,527
Fannie Mae [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading		32,253	35,395
Debt Securities, Trading and Available-for-sale		$ 40,542	$ 45,644
Weighted average coupon		3.15%	3.30%
Weighted average yield		2.37%	2.25%
Fannie Mae [Member] \| Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 7,615	$ 9,325
Unamortized discount		(3)	(4)
Unamortized premium		367	389
Amortized cost		7,979	9,710
Gross unrealized gains		310	539
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		8,289	10,249
Fannie Mae [Member] \| Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount		(15)	(18)
Unamortized premium		1,070	1,314
Debt Securities, Trading, Unrealized Gain		759	1,280
Debt Securities, Trading, Unrealized Loss		(109)	(5)
Trading Securities, Cost		31,603	34,120
Trading Securities Par		30,548	32,824
Freddie Mac [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading		14,835	15,735
Debt Securities, Trading and Available-for-sale		$ 17,594	$ 19,482
Weighted average coupon		3.23%	3.56%
Weighted average yield		2.38%	2.39%
Freddie Mac [Member] \| Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 2,538	$ 3,416
Unamortized discount		(1)	(1)
Unamortized premium		127	152
Amortized cost		2,664	3,567
Gross unrealized gains		95	180
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		2,759	3,747
Freddie Mac [Member] \| Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount		(3)	(1)
Unamortized premium		535	607
Debt Securities, Trading, Unrealized Gain		362	683
Debt Securities, Trading, Unrealized Loss		(51)	(1)
Trading Securities, Cost		14,524	15,053
Trading Securities Par		13,992	14,447
Ginnie Mae [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading		3	3
Debt Securities, Trading and Available-for-sale		$ 5	$ 5
Weighted average coupon		4.73%	4.73%
Weighted average yield		2.56%	2.46%
Ginnie Mae [Member] \| Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 2	$ 2
Unamortized discount		0	0
Unamortized premium		0	0
Amortized cost		2	2
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		2	2
Ginnie Mae [Member] \| Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount		0	0
Unamortized premium		0	0
Debt Securities, Trading, Unrealized Gain		0	0
Debt Securities, Trading, Unrealized Loss		0	0
Trading Securities, Cost		3	3
Trading Securities Par		3	3
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading		200	188
Debt Securities, Trading and Available-for-sale		$ 200	$ 188
Weighted average coupon		4.23%	4.28%
Weighted average yield		4.38%	4.33%
Mortgage-backed Securities, Issued by Private Enterprises [Member] \| Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 0	$ 0
Unamortized discount		0	0
Unamortized premium		0	0
Amortized cost		0	0
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		0	0
Mortgage-backed Securities, Issued by Private Enterprises [Member] \| Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount		(12)	(12)
Unamortized premium		3	4
Debt Securities, Trading, Unrealized Gain		13	11
Debt Securities, Trading, Unrealized Loss		0	(2)
Trading Securities, Cost		187	179
Trading Securities Par		196	187
Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading		353	358
Debt Securities, Trading and Available-for-sale		$ 353	$ 358
Weighted average coupon		3.69%	4.13%
Weighted average yield		4.01%	4.29%
Commercial Mortgage Backed Securities [Member] \| Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 0	$ 0
Unamortized discount		0	0
Unamortized premium		0	0
Amortized cost		0	0
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		0	0
Commercial Mortgage Backed Securities [Member] \| Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount		(6)	(3)
Unamortized premium		4	6
Debt Securities, Trading, Unrealized Gain		18	28
Debt Securities, Trading, Unrealized Loss		(1)	(4)
Trading Securities, Cost		336	334
Trading Securities Par		338	331
Credit Risk Transfer Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading		1,105	737
Debt Securities, Trading and Available-for-sale		$ 1,105	$ 737
Weighted average coupon		3.58%	3.43%
Weighted average yield		4.09%	3.71%
Credit Risk Transfer Securities [Member] \| Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 0	$ 0
Unamortized discount		0	0
Unamortized premium		0	0
Amortized cost		0	0
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		0	0
Credit Risk Transfer Securities [Member] \| Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount		(9)	(12)
Unamortized premium		13	10
Debt Securities, Trading, Unrealized Gain		26	12
Debt Securities, Trading, Unrealized Loss		(2)	(8)
Trading Securities, Cost		1,081	733
Trading Securities Par		1,077	735
Credit Risk Transfer Securities [Member] \| Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading and Available-for-sale		$ 1,105	$ 737

Stockholders' Equity (Common Stock Repurchase Program) (Details) - USD ($) shares in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of common stock shares		(15,000)
Repurchase of common stock, value	$ (147,000,000)	$ (239,000,000)	$ (147,000,000)
Payments for Repurchase of Common Stock		239,000,000	$ 147,000,000
Stock Repurchased During Period, Average Repurchase Price (in dollars per share)		16.00
Stock Repurchase Program, Remaining Authorized Repurchase Amount		684,000,000
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of common stock shares	(12,200)		(12,200)
Repurchase of common stock, value		$ 0

Repurchase Agreements And Reverse Repurchase Agreements (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) days	Dec. 31, 2020 USD ($) days
Assets Sold under Agreements to Repurchase [Line Items]
Receivable Under Reverse Repurchase Agreements		$ 11,979,000	$ 11,748,000
Securities Sold under Agreements to Repurchase		48,737,000	52,366,000
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value		$ 10,920,000	$ 11,727,000
Short-term Debt, Weighted Average Interest Rate, at Point in Time		0.11%	0.24%
Debt of consolidated variable interest entities, at fair value		$ (148,000)	$ (177,000)
Repurchase Agreements Extinguished - Extinguishment of Debt	$ 3,700,000
Weighted Average Remaining Maturity of Repurchase Agreements Extinguished - Extinguished Debt	2 years 2 months 12 days
Gain (Loss) on Extinguishment of Debt	$ (146,000)
Weighted Average Interest Rate of Repurchase Agreements Extinguished - Extinguished Debt	2.11%
TBA securities Fifteen Year and Thirty Year Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Fair Value, Net		79,000	275,000
TBA and Forward Settling Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Forward Settlement Value		27,307,000	31,204,000
Derivative, Fair Value, Net		79,000	275,000
Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		7,400,000	11,200,000
Forward Contracts [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		$ 8,300,000	$ 2,900,000
Weighted Average Forward Start Days \| days		2	4
Short-term Debt, Weighted Average Interest Rate, at Point in Time		0.06%	0.12%
Bethesda Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Percentage of Repurchase Agreement Funding		44.00%	47.00%
FICC [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Percentage of Repurchase Agreement Funding		43.00%	46.00%
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value		$ 2,700,000	$ 3,600,000

Pledged Assets (Tables)

6 Months Ended

Jun. 30, 2021

Pledged Assets [Abstract]

Schedule of Securities and Cash Pledged as Collateral from Counterparties [Table Text Block]

As of June 30, 2021 and December 31, 2020, we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions).


	June 30, 2021								December 31, 2020
Assets Pledged to AGNC	Reverse Repurchase Agreements		Derivative Agreements		Repurchase Agreements		Total		Reverse Repurchase Agreements		Derivative Agreements		Repurchase Agreements		Total
U.S. Treasury securities - fair value 1	$	13,023	$	—	$	13	$	13,036	$	11,727	$	—	$	13	$	11,740
Cash	—		314		1		315		—		107		3		110
Total	$	13,023	$	314	$	14	$	13,351	$	11,727	$	107	$	16	$	11,850

________________________________

1.As of June 30, 2021, $0.6 billion of U.S. Treasury securities received from counterparties were repledged as collateral. As of June 30, 2021 and December 31, 2020, $10.9 billion and $11.7 billion, respectively, of U.S. Treasury securities received from counterparties were used to cover short sales of U.S. Treasury securities.

Schedule of Financial Instruments Owned and Pledged as Collateral

The following tables summarize our assets pledged as collateral under our funding, derivative and brokerage and clearing agreements by type, including securities pledged related to securities sold but not yet settled, as of June 30, 2021 and December 31, 2020 (in millions):


	June 30, 2021
Assets Pledged to Counterparties 1	Repurchase Agreements 2		Debt of Consolidated VIEs		Derivative Agreements		Brokerage and Clearing Agreements 3		Total
Agency RMBS - fair value	$	49,044	$	245	$	483	$	404	$	50,176
CRT - fair value	502		—		—		—		502
Non-Agency - fair value	377		—		—		—		377
U.S. Treasury securities - fair value	733		—		—		272		1,005
Accrued interest on pledged securities	128		1		1		1		131
Restricted cash	19		—		604		—		623
Total	$	50,803	$	246	$	1,088	$	677	$	52,814


	December 31, 2020
Assets Pledged to Counterparties 1	Repurchase Agreements 2		Debt of Consolidated VIEs		Derivative Agreements		Brokerage and Clearing Agreements 3		Total
Agency RMBS - fair value	$	53,401	$	295	$	365	$	258	$	54,319
CRT - fair value	455		—		—		—		455
Non-Agency - fair value	458		—		—		—		458

Accrued interest on pledged securities	147		1		1		1		150
Restricted cash	417		—		890		—		1,307
Total	$	54,878	$	296	$	1,256	$	259	$	56,689

________________________________

1.Includes repledged assets received as collateral from counterparties and securities sold but not yet settled.

2.Includes $98 million and $119 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of June 30, 2021 and December 31, 2020, respectively.

3.Includes margin for TBAs cleared through prime brokers and other clearing deposits.

Schedules Of Securities Pledged As Collateral Under Repurchase Agreement

The following table summarizes our securities pledged as collateral under our repurchase agreements by the remaining maturity of our borrowings, including securities pledged related to sold but not yet settled securities, as of June 30, 2021 and December 31, 2020 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 4.


	June 30, 2021						December 31, 2020
Securities Pledged by Remaining Maturity of Repurchase Agreements 1,2	Fair Value of Pledged Securities		Amortized Cost of Pledged Securities		Accrued Interest on Pledged Securities		Fair Value of Pledged Securities		Amortized Cost of Pledged Securities		Accrued Interest on Pledged Securities
≤ 30 days	$	31,779	$	30,818	$	84	$	29,674	$	28,208	$	82
> 30 and ≤ 60 days	3,124		3,002		8		8,438		8,013		23
> 60 and ≤ 90 days	5,788		5,641		15		5,782		5,495		16
> 90 days	9,628		9,542		21		10,420		10,068		26
Total	$	50,319	$	49,003	$	128	$	54,314	$	51,784	$	147

________________________________

1.Includes $98 million and $119 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of June 30, 2021 and December 31, 2020, respectively.

2.Excludes $0.6 billion of repledged U.S. Treasury securities received as collateral from counterparties as of June 30, 2021.

Offsetting Assets and Liabilities

The following tables present information about our assets and liabilities that are subject to master netting arrangements and can potentially be offset on our consolidated balance sheets as of June 30, 2021 and December 31, 2020 (in millions):


	Offsetting of Financial and Derivative Assets
	Gross Amounts of Recognized Assets		Gross Amounts Offset in the Consolidated Balance Sheets		Net Amounts of Assets Presented in the Consolidated Balance Sheets		Gross Amounts Not Offset in the Consolidated Balance Sheets				Net Amount
							Financial Instruments		Collateral Received 2
June 30, 2021
Interest rate swap and swaption agreements, at fair value 1	$	294	$	—	$	294	$	—	$	(293)	$	1
TBA securities, at fair value	87		—		87		(8)		—		79
Receivable under reverse repurchase agreements	11,979		—		11,979		(7,216)		(4,763)		—
Total	$	12,360	$	—	$	12,360	$	(7,224)	$	(5,056)	$	80

December 31, 2020
Interest rate swap and swaption agreements, at fair value 1	$	116	$	—	$	116	$	—	$	(105)	$	11
TBA securities, at fair value	275		—		275		—		—		275
Receivable under reverse repurchase agreements	11,748		—		11,748		(6,522)		(5,223)		3
Total	$	12,139	$	—	$	12,139	$	(6,522)	$	(5,328)	$	289

Offsetting Liabilities


	Offsetting of Financial and Derivative Liabilities
	Gross Amounts of Recognized Liabilities		Gross Amounts Offset in the Consolidated Balance Sheets		Net Amounts of Liabilities Presented in the Consolidated Balance Sheets		Gross Amounts Not Offset in the Consolidated Balance Sheets				Net Amount
							Financial Instruments		Collateral Pledged 2
June 30, 2021

TBA securities, at fair value	$	8	$	—	$	8	$	(8)	$	—	$	—
Repurchase agreements	48,737		—		48,737		(7,216)		(41,520)		1
Total	$	48,745	$	—	$	48,745	$	(7,224)	$	(41,520)	$	1

December 31, 2020


Repurchase agreements	$	52,366	$	—	$	52,366	$	(6,522)	$	(45,844)	$	—
Total	$	52,366	$	—	$	52,366	$	(6,522)	$	(45,844)	$	—

________________________________

1.Reported under derivative assets / liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 5 for a reconciliation of derivative assets / liabilities, at fair value to their sub-components.

2.Includes cash and securities pledged / received as collateral, at fair value. Amounts include repledged collateral. Amounts presented are limited to collateral pledged sufficient to reduce the net amount to zero for individual counterparties, as applicable.

Investment Securities (Tables)

6 Months Ended

Jun. 30, 2021

Investments, Debt and Equity Securities [Abstract]

Securities by Credit Rating [Table Text Block]

As of June 30, 2021 and December 31, 2020, our investments in CRT and non-Agency securities had the following credit ratings (in millions):


	June 30, 2021						December 31, 2020
CRT and Non-Agency Security Credit Ratings 1	CRT		RMBS		CMBS		CRT		RMBS		CMBS
AAA	$	—	$	—	$	21	$	—	$	—	$	35
AA	—		20		118		—		20		190
A	—		36		39		—		32		28
BBB	72		77		50		28		83		55
BB	222		42		89		167		36		43
B	386		10		36		304		6		7
Not Rated	425		15		—		238		11		—
Total	$	1,105	$	200	$	353	$	737	$	188	$	358

________________________________

Available-for-sale Securities [Table Text Block]


	June 30, 2021
	Agency RMBS									Non-Agency
Investment Securities	Fannie Mae			Freddie Mac			Ginnie Mae			RMBS			CMBS			CRT			Total
Available-for-sale securities:
Par value	$	7,615		$	2,538		$	2		$	—		$	—		$	—		$	10,155
Unamortized discount	(3)			(1)			—			—			—			—			(4)
Unamortized premium	367			127			—			—			—			—			494
Amortized cost	7,979			2,664			2			—			—			—			10,645
Gross unrealized gains	310			95			—			—			—			—			405
Gross unrealized losses	—			—			—			—			—			—			—
Total available-for-sale securities, at fair value	8,289			2,759			2			—			—			—			11,050
Securities remeasured at fair value through earnings:
Par value	30,548			13,992			3			196			338			1,077			46,154
Unamortized discount	(15)			(3)			—			(12)			(6)			(9)			(45)
Unamortized premium	1,070			535			—			3			4			13			1,625
Amortized cost	31,603			14,524			3			187			336			1,081			47,734
Gross unrealized gains	759			362			—			13			18			26			1,178
Gross unrealized losses	(109)			(51)			—			—			(1)			(2)			(163)
Total securities remeasured at fair value through earnings	32,253			14,835			3			200			353			1,105			48,749
Total securities, at fair value	$	40,542		$	17,594		$	5		$	200		$	353		$	1,105		$	59,799
Weighted average coupon as of June 30, 2021	3.15		%	3.23		%	4.73		%	4.23		%	3.69		%	3.58		%	3.19		%
Weighted average yield as of June 30, 2021 1	2.37		%	2.38		%	2.56		%	4.38		%	4.01		%	4.09		%	2.42		%

________________________________

1.Incorporates a weighted average future constant prepayment rate assumption of 11.6% based on forward rates as of June 30, 2021.


	December 31, 2020
	Agency RMBS									Non-Agency
Investment Securities	Fannie Mae			Freddie Mac			Ginnie Mae			RMBS			CMBS			CRT			Total
Available-for-sale securities:
Par value	$	9,325		$	3,416		$	2		$	—		$	—		$	—		$	12,743
Unamortized discount	(4)			(1)			—			—			—			—			(5)
Unamortized premium	389			152			—			—			—			—			541
Amortized cost	9,710			3,567			2			—			—			—			13,279
Gross unrealized gains	539			180			—			—			—			—			719
Gross unrealized losses	—			—			—			—			—			—			—
Total available-for-sale securities, at fair value	10,249			3,747			2			—			—			—			13,998
Securities remeasured at fair value through earnings:
Par value	32,824			14,447			3			187			331			735			48,527
Unamortized discount	(18)			(1)			—			(12)			(3)			(12)			(46)
Unamortized premium	1,314			607			—			4			6			10			1,941
Amortized cost	34,120			15,053			3			179			334			733			50,422
Gross unrealized gains	1,280			683			—			11			28			12			2,014
Gross unrealized losses	(5)			(1)			—			(2)			(4)			(8)			(20)
Total securities remeasured at fair value through earnings	35,395			15,735			3			188			358			737			52,416
Total securities, at fair value	$	45,644		$	19,482		$	5		$	188		$	358		$	737		$	66,414
Weighted average coupon as of December 31, 2020	3.30		%	3.56		%	4.73		%	4.28		%	4.13		%	3.43		%	3.39		%
Weighted average yield as of December 31, 2020 1	2.25		%	2.39		%	2.46		%	4.33		%	4.29		%	3.71		%	2.33		%

________________________________

1.Incorporates a weighted average future constant prepayment rate assumption of 17.6% based on forward rates as of December 31, 2020.

Components of Investment Securities


	June 30, 2021				December 31, 2020
Investment Securities	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Agency RMBS:
Fixed rate	$	56,418	$	57,757	$	61,977	$	64,615
Adjustable rate	54		56		69		70
CMO	219		228		289		301
Interest-only and principal-only strips	84		100		105		126
Multifamily	—		—		17		19
Total Agency RMBS	56,775		58,141		62,457		65,131
Non-Agency RMBS	187		200		178		188
CMBS	336		353		333		358
CRT securities	1,081		1,105		733		737
Total investment securities	$	58,379	$	59,799	$	63,701	$	66,414

Summary Of Agency Securities Estimated Weighted Average Life Classifications

The following table summarizes our investments as of June 30, 2021 and December 31, 2020 according to their estimated weighted average life classification (dollars in millions):


	June 30, 2021						December 31, 2020
Estimated Weighted Average Life of Investment Securities	Fair Value		Amortized Cost		Weighted Average Coupon	Weighted Average Yield	Fair Value		Amortized Cost		Weighted Average Coupon	Weighted Average Yield
≤ 3 years	$	1,407	$	1,370	3.59%	2.69%	$	3,642	$	3,569	3.56%	2.15%
> 3 years and ≤ 5 years	15,366		14,905		3.62%	2.49%	47,740		45,578		3.54%	2.42%
> 5 years and ≤10 years	40,176		39,276		3.07%	2.41%	15,019		14,541		2.87%	2.08%
> 10 years	2,850		2,828		2.32%	2.09%	13		13		5.56%	3.59%
Total	$	59,799	$	58,379	3.19%	2.42%	$	66,414	$	63,701	3.39%	2.33%

Summary of Net Gain from Sale of Agency Securities


	Three Months Ended June 30,
	2021						2020
Investment Securities	Available-for-Sale Securities 2		Fair Value Option Securities		Total		Available-for-Sale Securities 2		Fair Value Option Securities		Total
Investment securities sold, at cost	$	(4,151)	$	(8,659)	$	(12,810)	$	(1,278)	$	(4,472)	$	(5,750)
Proceeds from investment securities sold 1	4,165		8,670		12,835		1,317		4,586		5,903
Net gain (loss) on sale of investment securities	$	14	$	11	$	25	$	39	$	114	$	153

Gross gain on sale of investment securities	$	14	$	48	$	62	$	39	$	129	$	168
Gross loss on sale of investment securities	—		(37)		(37)		—		(15)		(15)
Net gain (loss) on sale of investment securities	$	14	$	11	$	25	$	39	$	114	$	153


	Six Months Ended June 30,
	2021						2020
Investment Securities	Available-for-Sale Securities 2		Fair Value Option Securities		Total		Available-for-Sale Securities 2		Fair Value Option Securities		Total
Investment securities sold, at cost	$	(4,644)	$	(14,523)	$	(19,167)	$	(1,433)	$	(53,912)	$	(55,345)
Proceeds from investment securities sold 1	4,676		14,503		19,179		1,473		54,519		55,992
Net gain (loss) on sale of investment securities	$	32	$	(20)	$	12	$	40	$	607	$	647

Gross gain on sale of investment securities	$	32	$	97	$	129	$	40	$	696	$	736
Gross loss on sale of investment securities	—		(117)		(117)		—		(89)		(89)
Net gain (loss) on sale of investment securities	$	32	$	(20)	$	12	$	40	$	607	$	647

________________________________

1.Proceeds include cash received during the period, plus receivable for investment securities sold during the period as of period end.

2.See Note 9 for a summary of changes in accumulated OCI.

Derivative and Other Hedging Instruments

6 Months Ended

Jun. 30, 2021

Derivative Instruments and Hedging Activities Disclosure [Abstract]

US Government Futures Securities [Table Text Block]


U.S. Treasury Futures	June 30, 2021								December 31, 2020
Maturity	Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1		Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1
10 years	$	(1,500)	$	(1,982)	$	(1,988)	$	(6)	$	(1,000)	$	(1,379)	$	(1,381)	$	(2)

________________________________

1.Net carrying value represents the difference between the fair market value and the cost basis (or the forward price to be paid/(received) for the underlying U.S. Treasury security) of the U.S. Treasury futures contract as of period-end and is reported in derivative assets/(liabilities), at fair value in our consolidated balance sheets.

Derivative and Other Hedging Instruments

Derivative and Other Hedging InstrumentsWe hedge a portion of our interest rate risk primarily utilizing interest rate swaps, interest rate swaptions, U.S. Treasury securities and U.S. Treasury futures contracts. We utilize TBA securities primarily as a means of investing in the Agency securities market. For additional information regarding our derivative instruments and our overall risk management strategy, please refer to the discussion of derivative and other hedging instruments in Note 2.

Derivative and Other Hedging Instrument Assets (Liabilities), at Fair Value

The table below summarizes fair value information about our derivative and other hedging instrument assets/(liabilities) as of June 30, 2021 and December 31, 2020 (in millions):



Derivative and Other Hedging Instruments	Balance Sheet Location	June 30, 2021		December 31, 2020

Swaptions	Derivative assets, at fair value	$	294	$	116
TBA securities	Derivative assets, at fair value	87		275

Total derivative assets, at fair value		$	381	$	391


TBA securities	Derivative liabilities, at fair value	(8)		—
U.S. Treasury futures - short	Derivative liabilities, at fair value	(6)		(2)
Total derivative liabilities, at fair value		$	(14)	$	(2)

U.S. Treasury securities - long	U.S. Treasury securities, at fair value	$	397	$	—
U.S. Treasury securities - short	Obligation to return securities borrowed under reverse repurchase agreements, at fair value	(10,920)		(11,727)
Total U.S. Treasury securities, net at fair value		$	(10,523)	$	(11,727)

The following tables summarize certain characteristics of our derivative and other hedging instruments outstanding as of June 30, 2021 and December 31, 2020 (dollars in millions):


	June 30, 2021					December 31, 2020
Pay Fixed / Receive Variable Interest Rate Swaps	Notional Amount		Average Fixed Pay Rate	Average Receive Rate	Average Maturity (Years)	Notional Amount		Average Fixed Pay Rate	Average Receive Rate	Average Maturity (Years)
≤ 3 years	$	16,000	0.11%	0.06%	2.3	$	8,750	0.04%	0.08%	2.4
> 3 to ≤ 5 years	18,500		0.13%	0.06%	3.9	17,000		0.10%	0.08%	4.1
> 5 to ≤ 7 years	7,050		0.21%	0.05%	5.5	9,800		0.21%	0.08%	5.8
> 7 to ≤ 10 years	6,700		0.36%	0.05%	8.1	6,200		0.28%	0.07%	8.5
> 10 years	1,475		0.47%	0.06%	13.7	1,475		0.47%	0.07%	14.2
Total	$	49,725	0.18%	0.06%	4.4	$	43,225	0.15%	0.08%	5.1


Pay Fixed / Receive Variable Interest Rate Swaps by Receive Index (% of Notional Amount)	June 30, 2021		December 31, 2020
SOFR	74	%	71	%
OIS	26	%	29	%
Total	100	%	100	%


Swaptions	Option					Underlying Payer Swap
Current Option Expiration Date	Cost Basis		Fair Value		Average Months to Current Option Expiration Date 1	Notional Amount		Average Fixed Pay Rate 2	Average Term (Years)
June 30, 2021
≤ 1 year	$	101	$	55	5	$	4,200	1.77%	8.8
> 1 year ≤ 2 years	80		117		20	3,250		1.41%	10.0
> 2 year ≤ 3 years	110		122		32	4,000		2.07%	10.0

Total	$	291	$	294	19	$	11,450	1.77%	9.5

December 31, 2020
≤ 1 year	$	123	$	15	5	$	5,900	2.17%	9.2
> 1 year ≤ 2 years	41		33		20	2,000		1.38%	10.0
> 2 year ≤ 3 years	65		60		33	2,250		1.40%	10.0
> 3 year ≤ 4 years	8		8		40	250		1.43%	10.0
Total	$	237	$	116	15	$	10,400	1.84%	9.5

________________________________

1.As of June 30, 2021 and December 31, 2020, ≤ 1 year notional amount includes $700 million of Bermudan swaptions where the options may be exercised on predetermined dates up to their final exercise date, which is six months prior to the underlying swaps' maturity date.

2.As of June 30, 2021, 8% and 92% of the underlying swap receive rates were tied to 3-Month LIBOR and SOFR, respectively. As of December 31, 2020, 33% and 67% of the underlying payer swap receive rates were tied to 3-Month LIBOR and SOFR, respectively.


U.S. Treasury Securities	June 30, 2021						December 31, 2020
Maturity	Face Amount Long/(Short)		Cost Basis 1		Fair Value		Face Amount Long/(Short)		Cost Basis 1		Fair Value
5 years	$	(1,665)	$	(1,648)	$	(1,631)	$	(425)	$	(425)	$	(425)
7 years	(1,083)		(1,072)		(1,049)		(1,083)		(1,081)		(1,089)
10 years	(7,748)		(7,740)		(7,843)		(9,780)		(9,862)		(10,213)
Total U.S. Treasury securities	$	(10,496)	$	(10,460)	$	(10,523)	$	(11,288)	$	(11,368)	$	(11,727)

________________________________

1.As of June 30, 2021 and December 31, 2020, short U.S. Treasury securities had a weighted average yield of 1.30% and 1.20%, respectively, and long U.S. Treasury securities totaling $397 million, at fair value, had a weighted average yield of 0.98% as of June 30, 2021.


U.S. Treasury Futures	June 30, 2021								December 31, 2020
Maturity	Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1		Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1
10 years	$	(1,500)	$	(1,982)	$	(1,988)	$	(6)	$	(1,000)	$	(1,379)	$	(1,381)	$	(2)

________________________________


	June 30, 2021								December 31, 2020
TBA Securities by Coupon	Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1		Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1
15-Year TBA securities:
≤ 2.0%	$	418	$	422	$	423	1		$	6,540	$	6,708	$	6,771	$	63
2.5%	328		342		342		—		200		208		209		1



Total 15-Year TBA securities	746		764		765		1		6,740		6,916		6,980		64
30-Year TBA securities:
≤ 2.0%	2,551		2,552		2,572		20		19,805		20,314		20,480		166
2.5%	20,627		21,227		21,289		62		3,167		3,291		3,335		44
3.0%	2,104		2,195		2,193		(2)		528		552		553		1
3.5%	539		569		567		(2)		124		131		131		—


Total 30-Year TBA securities, net	25,821		26,543		26,621		78		23,624		24,288		24,499		211
Total TBA securities, net	$	26,567	$	27,307	$	27,386	$	79	$	30,364	$	31,204	$	31,479	$	275

________________________________

1.Net carrying value represents the difference between the fair market value and the cost basis (or the forward price to be paid/(received) for the underlying Agency security) of the TBA contract as of period-end and is reported in derivative assets/(liabilities), at fair value in our consolidated balance sheets.

Gain (Loss) From Derivative Instruments and Other Securities, Net

The following table summarizes changes in our derivative and other hedge portfolio and their effect on our consolidated statements of comprehensive income for the three and six months ended June 30, 2021 and 2020 (in millions):


Derivative and Other Hedging Instruments	Beginning Notional Amount		Additions	Settlement, Termination, Expiration or Exercise	Ending Notional Amount		Gain/(Loss) on Derivative Instruments and Other Securities, Net 1
Three months ended June 30, 2021:
TBA securities, net	$	24,518	94,248	(92,199)	$	26,567	$	396
Forward settling non-Agency securities	$	—	300	—	$	300	—
Interest rate swaps - payer	$	49,725	—	—	$	49,725	(400)
Payer swaptions	$	13,150	—	(1,700)	$	11,450	(313)
U.S. Treasury securities - short position	$	(15,527)	(585)	5,219	$	(10,893)	(333)
U.S. Treasury securities - long position	$	—	1,336	(939)	$	397	(1)
U.S. Treasury futures contracts - short position	$	(1,000)	(2,000)	1,500	$	(1,500)	(29)
							$	(680)
Three months ended June 30, 2020:
TBA securities, net	$	20,279	75,186	(75,705)	$	19,760	$	220
Interest rate swaps - payer	$	46,475	25,750	(30,150)	$	42,075	(379)
Payer swaptions	$	9,550	—	(200)	$	9,350	(14)
U.S. Treasury securities - short position	$	(4,245)	(4,187)	1,185	$	(7,247)	(60)
U.S. Treasury securities - long position	$	3,569	550	(2,987)	$	1,132	4
U.S. Treasury futures contracts - short position	$	(1,000)	(1,000)	1,000	$	(1,000)	(8)
							$	(237)


Six months ended June 30, 2021:
TBA securities, net	$	30,364	187,584	(191,381)	$	26,567	$	(530)
Forward settling non-Agency securities	$	—	300	—	$	300	—
Interest rate swaps - payer	$	43,225	7,000	(500)	$	49,725	724
Payer swaptions	$	10,400	4,250	(3,200)	$	11,450	74
U.S. Treasury securities - short position	$	(11,287)	(7,846)	8,240	$	(10,893)	474
U.S. Treasury securities - long position	$	—	2,651	(2,254)	$	397	(11)
U.S. Treasury futures contracts - short position	$	(1,000)	(3,000)	2,500	$	(1,500)	32
							$	763
Six months ended June 30, 2020:
TBA securities, net	$	7,322	112,936	(100,498)	$	19,760	$	913
Interest rate swaps - payer	$	79,075	75,725	(112,725)	$	42,075	(3,174)
Payer swaptions	$	8,850	2,000	(1,500)	$	9,350	(148)
U.S. Treasury securities - short position	$	(9,224)	(10,232)	12,209	$	(7,247)	(997)
U.S. Treasury securities - long position	$	95	7,011	(5,974)	$	1,132	101
U.S. Treasury futures contracts - short position	$	(1,000)	(2,000)	2,000	$	(1,000)	(112)
							$	(3,417)

________________________________

1.Amounts exclude other miscellaneous gains and losses recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income.

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2021	Jul. 31, 2021
Entity Information [Line Items]
Entity Incorporation, State or Country Code	DE
Document Transition Report	false
Document Quarterly Report	true
Entity Tax Identification Number	26-1701984
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2021
Entity File Number	001-34057
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Registrant Name	AGNC INVESTMENT CORP.
Entity Address, Address Line One	2 Bethesda Metro Center, 12th Floor
Entity Address, City or Town	Bethesda
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20814
City Area Code	301
Local Phone Number	968-9315
Entity Central Index Key	0001423689
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		524,908,382
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Common Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	AGNC
Security Exchange Name	NASDAQ
Depository shares each representing a 1/1,000th interest in a share of 7.000% Series C Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Depositary shares of 7.000% Series C Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Trading Symbol	AGNCN
Security Exchange Name	NASDAQ
Depository shares each representing a 1/1,000th interest in a share of 6.875% Series D Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Depositary shares of 6.875% Series D Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Trading Symbol	AGNCM
Security Exchange Name	NASDAQ
Depository shares each representing a 1/1000th interest in a share of 6.500% Series E Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Depositary shares of 6.50% Series E Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Trading Symbol	AGNCO
Security Exchange Name	NASDAQ
Depositary shares each representing a 1/1000th interest in a share of 6.125% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Depositary shares of 6.125% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock
Trading Symbol	AGNCP
Security Exchange Name	NASDAQ

Organization	6 Months Ended
Organization	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization AGNC Investment Corp. (referred throughout this report as the "Company," "we," "us" and "our") was organized in Delaware on January 7, 2008 and commenced operations on May 20, 2008 following the completion of our initial public offering. Our common stock is traded on The Nasdaq Global Select Market under the symbol "AGNC." We invest primarily in Agency residential mortgage-backed securities ("Agency RMBS") for which the principal and interest payments are guaranteed by a U.S. Government-sponsored enterprise ("GSE") or a U.S. Government agency. We also invest in other types of mortgage and mortgage-related securities, such as credit risk transfer ("CRT") securities and non-Agency residential and commercial mortgage-backed securities ("non-Agency RMBS" and "CMBS," respectively), where repayment of principal and interest is not guaranteed by a GSE or U.S. Government agency, and other assets related to the housing, mortgage or real estate markets. We fund our investments primarily through collateralized borrowings structured as repurchase agreements. We operate to qualify to be taxed as a real estate investment trust ("REIT") under the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code"). As a REIT, we are required to distribute annually 90% of our taxable income, and we will generally not be subject to U.S. federal or state corporate income tax to the extent that we distribute our annual taxable income to our stockholders on a timely basis. It is our intention to distribute 100% of our taxable income, after application of available tax attributes, within the limits prescribed by the Internal Revenue Code, which may extend into the subsequent tax year. We are internally managed with the principal objective of providing our stockholders with attractive risk-adjusted returns through a combination of monthly dividends and tangible net book value accretion. We generate income from the interest earned on our investments, net of associated borrowing and hedging costs, and net realized gains and losses on our investment and hedging activities.

Summary of Significant Accounting Policies Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Derivatives, Policy [Policy Text Block]	Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate, prepayment, extension and liquidity risks. The objective of our risk management strategy is to reduce fluctuations in net book value over a range of interest rate scenarios. In particular, we attempt to mitigate the risk of the cost of our variable rate liabilities increasing during a period of rising interest rates. The primary instruments that we use are interest rate swaps, options to enter into interest rate swaps ("swaptions"), U.S. Treasury securities and U.S. Treasury futures contracts. We also use forward contracts in the Agency RMBS "to-be-announced" market, or TBA securities, to invest in and finance Agency securities and to periodically reduce our exposure to Agency RMBS. We account for derivative instruments in accordance with ASC Topic 815, Derivatives and Hedging ("ASC 815"). ASC 815 requires an entity to recognize all derivatives as either assets or liabilities in our accompanying consolidated balance sheets and to measure those instruments at fair value. None of our derivative instruments have been designated as hedging instruments for accounting purposes under the provisions of ASC 815, consequently changes in the fair value of our derivative instruments are reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with the counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. Derivative instruments in a gain position are reported as derivative assets at fair value and derivative instruments in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Changes in fair value of derivative instruments and periodic settlements related to our derivative instruments are recorded in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. Interest rate swap agreements We use interest rate swaps to economically hedge the variable cash flows associated with our borrowings made under repurchase agreements. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate ("payer swaps") based on a short-term benchmark rate, such as the Secured Overnight Financing Rate ("SOFR"), Overnight Index Swap Rate ("OIS") or three-month London Interbank Offered Rate ("LIBOR"). Our interest rate swaps typically have terms from one to 10 years but may extend up to 20 years or more. Our interest rate swaps are centrally cleared through a registered commodities exchange. The clearing exchange requires that we post an "initial margin" amount determined by the exchange, which is generally intended to be set at a level sufficient to protect the exchange from the interest rate swap's maximum estimated single-day price movement. We also exchange daily settlements of "variation margin" based upon changes in fair value, as measured by the exchange. Pursuant to rules governing central clearing activities, we recognize variation margin settlements as a direct reduction of the carrying value of the interest rate swap asset or liability. Interest rate swaptions We purchase interest rate swaptions to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. Interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay and receive interest rates in the future. Our interest rate swaption agreements are not subject to central clearing. The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. The difference between the premium paid and the fair value of the swaption is reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid. If we sell or exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the cash or the fair value of the underlying interest rate swap and the premium paid. TBA securities A TBA security is a forward contract for the purchase or sale of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS to be delivered into the contract are not known until shortly before the settlement date. We may choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting TBA position, net settling the offsetting positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date (together referred to as a "dollar roll transaction"). The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to equivalent securities settling in the current month. This difference, or "price drop," is the economic equivalent of interest income on the underlying Agency securities, less an implied funding cost, over the forward settlement period (referred to as "dollar roll income"). Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. We account for TBA contracts as derivative instruments since either the TBA contracts do not settle in the shortest period of time possible or we cannot assert that it is probable at inception and throughout the term of the TBA contract that we will physically settle the contract on the settlement date. We account for TBA dollar roll transactions as a series of derivative transactions. U.S. Treasury securities We use U.S. Treasury securities and U.S. Treasury futures contracts to mitigate the potential impact of changes in interest rates on the performance of our portfolio. We borrow U.S. Treasury securities under reverse repurchase agreements to cover short sales of U.S. Treasury securities. We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on our accompanying consolidated balance sheets based on the value of the underlying U.S. Treasury security as of the reporting date. Gains and losses associated with U.S. Treasury securities and U.S. Treasury futures contracts are recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income.
Investment, Policy [Policy Text Block]	Investment Securities Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") guaranteed by the Federal National Mortgage Association ("Fannie Mae"), Federal Home Loan Mortgage Corporation ("Freddie Mac," and together with Fannie Mae, the "GSEs") or the Government National Mortgage Association ("Ginnie Mae"). CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third-party market participants, that synthetically transfer a portion of the risk associated with credit losses within pools of conventional residential mortgage loans from the GSEs and/or third parties to private investors. Unlike Agency RMBS, full repayment of the original principal balance of CRT securities is not guaranteed by a GSE or U.S. Government agency; rather, "credit risk transfer" is achieved by writing down the outstanding principal balance of the CRT securities if credit losses on a related pool of loans exceed certain thresholds. By reducing the amount that they are obligated to repay to holders of CRT securities, the GSEs and/or other third parties offset credit losses on the related loans. Non-Agency RMBS and CMBS (together, "Non-Agency MBS") are backed by residential and commercial mortgage loans, respectively, packaged and securitized by a private institution, such as a commercial bank. Non-Agency MBS typically benefit from credit enhancements derived from structural elements, such as subordination, overcollateralization or insurance, but nonetheless carry a higher level of credit exposure than Agency RMBS. All of our securities are reported at fair value on our consolidated balance sheet. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities, requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for securities pursuant to ASC Topic 825, Financial Instruments. Prior to fiscal year 2017, we primarily designated our investment securities as available-for-sale. On January 1, 2017, we began electing the fair value option of accounting for all investment securities newly acquired after such date. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income ("OCI"), whereas unrealized gains and losses on securities for which we elected the fair value option, or are classified as trading, are reported in net income through other gain (loss). Upon the sale of a security designated as available-for-sale, we determine the cost of the security and the amount of unrealized gain or loss to reclassify out of accumulated OCI into earnings based on the specific identification method. In our view, the election of the fair value option simplifies the accounting for investment securities and more appropriately reflects the results of our operations for a reporting period by presenting the fair value changes for these assets in a manner consistent with the presentation and timing of the fair value changes for our derivative instruments. We generally recognize gains or losses through net income on available-for-sale securities only if the security is sold; however, if the fair value of a security declines below its amortized cost and we determine that it is more likely than not that we will incur a realized loss on the security when we sell the asset, we will recognize the difference between the amortized cost and the fair value in net income as a component of other gain (loss). Since all of our available-for-sale designated securities consist of Agency RMBS, we do not have an allowance for credit losses. We have not recognized impairment losses on our available-for-sale securities through net income for the periods presented in our consolidated financial statements.
Interest Income [Policy Text Block]	Interest Income Interest income is accrued based on the outstanding principal amount of the investment securities and their contractual terms. Premiums or discounts associated with the purchase of Agency RMBS and non-Agency MBS of high credit quality are amortized or accreted into interest income, respectively, over the projected lives of the securities, including contractual payments and estimated prepayments, using the effective interest method in accordance with ASC Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs. We estimate long-term prepayment speeds of our mortgage securities using a third-party service and market data. The third-party service provider estimates prepayment speeds using models that incorporate the forward yield curve, primary to secondary mortgage rate spreads, current mortgage rates, mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, interest rate volatility and other factors. We review the prepayment speeds estimated by the third-party service for reasonableness with consideration given to both historical prepayment speeds and current market conditions. If based on our assessment, we believe that the third-party model does not fully reflect our expectations of the current prepayment landscape, such as during periods of elevated market uncertainty or unique market conditions, we may make adjustments to the models. We review our actual and anticipated prepayment experience on at least a quarterly basis and effective yields are recalculated when differences arise between (i) our previous estimate of future prepayments and (ii) actual prepayments to date and our current estimate of future prepayments. We are required to record an adjustment in the current period to premium amortization / discount accretion for the cumulative effect of the difference in the effective yields as if the recalculated yield had been in place as of the security's acquisition date through the reporting date. At the time we purchase CRT securities and non-Agency MBS that are not of high credit quality, we determine an effective yield based on our estimate of the timing and amount of future cash flows and our cost basis. Our initial cash flow estimates for these investments are based on our observations of current information and events and include assumptions related to interest rates, prepayment rates and the impact of default and severity rates on the timing and amount of credit losses. On at least a quarterly basis, we review the estimated cash flows and make appropriate adjustments based on inputs and analysis received from external sources, internal models, and our judgment regarding such inputs and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment adjusted for credit impairments, if any.

Stockholders' Equity (Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	6 Months Ended
	Feb. 11, 2020	Oct. 03, 2019	May 31, 2014	Jun. 30, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock E, Value, Issued		$ 390,000
Preferred Stock E, Liquidation Preference, Value		$ 403,000
Preferred Stock F, Value, Issued	$ 557,000
Preferred Stock D, Value, Issued				$ 227,000
Preferred Stock D, Liquidation Preference, Value				235,000
Preferred Stock C, Value, Issued				315,000
Preferred Stock C, Liquidation Preference, Value				325,000
Preferred Stock, Value, Issued				1,489,000	$ 1,489,000
Preferred Stock, Liquidation Preference, Value				$ 1,538,000	$ 1,538,000
Preferred Stock, Shares Authorized				10,000,000.0
Series B Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Percent Interest Per Share			0.10%
Series C Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance				13,800
Preferred Stock, Dividend Rate, Percentage				7.00%
Preferred Stock Dividend Payment Rate Variable Rate Spread				5.111%
Preferred Stock, Liquidation Preference Per Share				$ 25.00
Preferred Stock, Shares Issued				13,000
Series D Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance				10,350
Preferred Stock, Dividend Rate, Percentage				6.875%
Preferred Stock Dividend Payment Rate Variable Rate Spread				4.332%
Preferred Stock, Shares Issued				9,400
Series E Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance				16,100
Preferred Stock, Dividend Rate, Percentage		6.50%
Preferred Stock, Shares Issued				16,100
Series F Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance				23,000
Preferred Stock, Dividend Rate, Percentage	6.125%
Preferred Stock, Shares Issued				23,000
Preferred Stock, Liquidation Preference, Value	$ 575,000
Depositary Share [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued				61,500,000
Depositary Share [Member] \| Series C Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued				13,000,000.0
Depositary Share [Member] \| Series D Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued				9,400,000
Depositary Share [Member] \| Series E Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued		16,100,000
Depositary Share [Member] \| Series F Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued	23,000,000.0

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis


	June 30, 2021						December 31, 2020
	Level 1		Level 2		Level 3		Level 1		Level 2		Level 3
Assets:
Agency securities	$	—	$	57,896	$	—	$	—	$	64,836	$	—
Agency securities transferred to consolidated VIEs	—		245		—		—		295		—
Credit risk transfer securities	—		1,105		—		—		737		—
Non-Agency securities	—		553		—		—		546		—
U.S. Treasury securities	397		—		—		—		—		—
Interest rate swaps	—		—		—		—		—		—
Swaptions	—		294		—		—		116		—
TBA securities	—		87		—		—		275		—

Total	$	397	$	60,180	$	—	$	—	$	66,805	$	—
Liabilities:
Debt of consolidated VIEs	$	—	$	148	$	—	$	—	$	177	$	—
Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements	10,920		—		—		11,727		—		—
Interest rate swaps	—		—		—		—		—		—
TBA securities	—		8		—		—		—		—
U.S. Treasury futures	6		—		—		2		—		—
Total	$	10,926	$	156	$	—	$	11,729	$	177	$	—

Fair Value Measurements (Details) - USD ($) $ in Millions	6 Months Ended
Fair Value Measurements (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Future [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	$ 6	$ 2
Interest Rate Swaption [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	294	116
Interest Rate Swap [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0	0
Interest Rate Swap [Member] \| Derivative liabilities, at fair value [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0	0
Purchases Of TBAs And Forward Settling Agency Securities [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| TBA and Forward Settling Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
TBA securities	(87)	(275)
Securities Sold under Agreements to Repurchase	$ 48,737	52,366
Transfers between hierarchy levels	no
Agency securities	$ 57,896	64,836
Non-Agency Securities, at Fair Value	553	546
Financial Instruments, Owned, Other, at Fair Value	1,105	737
U.S. Treasury securities	397	0
TBA securities	(381)	(391)
Derivative Liability	14	2
Debt of consolidated variable interest entities, at fair value	148	177
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	10,920	11,727
Interest rate swaps	381	391
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	397	0
Total liabilities	10,926	11,729
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	60,180	66,805
Total liabilities	156	177
Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Sale Of TBA And Forward Settling Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	$ 8	$ 0

Summary of Significant Accounting Policies (Policy)	6 Months Ended
Summary of Significant Accounting Policies (Policy)	Jun. 30, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Basis of Presentation and Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Basis of Presentation Our accompanying consolidated financial statements and related notes have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Article 10 of Regulation S-X. The accompanying consolidated financial statements and related notes are unaudited and include the accounts of all our wholly-owned subsidiaries and variable interest entities for which we are the primary beneficiary. Significant intercompany accounts and transactions have been eliminated. The accompanying consolidated financial statements and related notes should be read in conjunction with the audited consolidated financial statements included in our most recent Annual Report on Form 10-K for the fiscal year ended December 31, 2020. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of income and expenses during the reporting period. In the opinion of management, all adjustments, consisting solely of normal recurring accruals, necessary for the fair presentation of consolidated financial statements for the interim period have been included. The current period’s results of operations are not necessarily indicative of results that ultimately may be achieved for the year. Investment Securities Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") guaranteed by the Federal National Mortgage Association ("Fannie Mae"), Federal Home Loan Mortgage Corporation ("Freddie Mac," and together with Fannie Mae, the "GSEs") or the Government National Mortgage Association ("Ginnie Mae"). CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third-party market participants, that synthetically transfer a portion of the risk associated with credit losses within pools of conventional residential mortgage loans from the GSEs and/or third parties to private investors. Unlike Agency RMBS, full repayment of the original principal balance of CRT securities is not guaranteed by a GSE or U.S. Government agency; rather, "credit risk transfer" is achieved by writing down the outstanding principal balance of the CRT securities if credit losses on a related pool of loans exceed certain thresholds. By reducing the amount that they are obligated to repay to holders of CRT securities, the GSEs and/or other third parties offset credit losses on the related loans. Non-Agency RMBS and CMBS (together, "Non-Agency MBS") are backed by residential and commercial mortgage loans, respectively, packaged and securitized by a private institution, such as a commercial bank. Non-Agency MBS typically benefit from credit enhancements derived from structural elements, such as subordination, overcollateralization or insurance, but nonetheless carry a higher level of credit exposure than Agency RMBS. All of our securities are reported at fair value on our consolidated balance sheet. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities, requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for securities pursuant to ASC Topic 825, Financial Instruments. Prior to fiscal year 2017, we primarily designated our investment securities as available-for-sale. On January 1, 2017, we began electing the fair value option of accounting for all investment securities newly acquired after such date. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income ("OCI"), whereas unrealized gains and losses on securities for which we elected the fair value option, or are classified as trading, are reported in net income through other gain (loss). Upon the sale of a security designated as available-for-sale, we determine the cost of the security and the amount of unrealized gain or loss to reclassify out of accumulated OCI into earnings based on the specific identification method. In our view, the election of the fair value option simplifies the accounting for investment securities and more appropriately reflects the results of our operations for a reporting period by presenting the fair value changes for these assets in a manner consistent with the presentation and timing of the fair value changes for our derivative instruments. We generally recognize gains or losses through net income on available-for-sale securities only if the security is sold; however, if the fair value of a security declines below its amortized cost and we determine that it is more likely than not that we will incur a realized loss on the security when we sell the asset, we will recognize the difference between the amortized cost and the fair value in net income as a component of other gain (loss). Since all of our available-for-sale designated securities consist of Agency RMBS, we do not have an allowance for credit losses. We have not recognized impairment losses on our available-for-sale securities through net income for the periods presented in our consolidated financial statements. Interest Income Interest income is accrued based on the outstanding principal amount of the investment securities and their contractual terms. Premiums or discounts associated with the purchase of Agency RMBS and non-Agency MBS of high credit quality are amortized or accreted into interest income, respectively, over the projected lives of the securities, including contractual payments and estimated prepayments, using the effective interest method in accordance with ASC Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs. We estimate long-term prepayment speeds of our mortgage securities using a third-party service and market data. The third-party service provider estimates prepayment speeds using models that incorporate the forward yield curve, primary to secondary mortgage rate spreads, current mortgage rates, mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, interest rate volatility and other factors. We review the prepayment speeds estimated by the third-party service for reasonableness with consideration given to both historical prepayment speeds and current market conditions. If based on our assessment, we believe that the third-party model does not fully reflect our expectations of the current prepayment landscape, such as during periods of elevated market uncertainty or unique market conditions, we may make adjustments to the models. We review our actual and anticipated prepayment experience on at least a quarterly basis and effective yields are recalculated when differences arise between (i) our previous estimate of future prepayments and (ii) actual prepayments to date and our current estimate of future prepayments. We are required to record an adjustment in the current period to premium amortization / discount accretion for the cumulative effect of the difference in the effective yields as if the recalculated yield had been in place as of the security's acquisition date through the reporting date. At the time we purchase CRT securities and non-Agency MBS that are not of high credit quality, we determine an effective yield based on our estimate of the timing and amount of future cash flows and our cost basis. Our initial cash flow estimates for these investments are based on our observations of current information and events and include assumptions related to interest rates, prepayment rates and the impact of default and severity rates on the timing and amount of credit losses. On at least a quarterly basis, we review the estimated cash flows and make appropriate adjustments based on inputs and analysis received from external sources, internal models, and our judgment regarding such inputs and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment adjusted for credit impairments, if any. Repurchase Agreements We finance the acquisition of securities for our investment portfolio primarily through repurchase agreements with financial institutions. Repurchase arrangements involve the sale and a simultaneous agreement to repurchase the transferred assets at a future date. We maintain a beneficial interest in the specific securities pledged during the term of each repurchase arrangement and we receive the related principal and interest payments. Pursuant to ASC Topic 860, Transfers and Servicing, we account for repurchase agreements as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest. Our repurchase agreements typically have maturities of less than one year but may extend up to five years or more. Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivative Instruments below). We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on the balance sheet based on the value of the underlying borrowed securities as of the reporting date. We may also enter into reverse repurchase agreements to earn a yield on excess cash balances. The securities received as collateral in connection with our reverse repurchase agreements mitigate our credit risk exposure to counterparties. Our reverse repurchase agreements typically have maturities of 30 days or less. Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate, prepayment, extension and liquidity risks. The objective of our risk management strategy is to reduce fluctuations in net book value over a range of interest rate scenarios. In particular, we attempt to mitigate the risk of the cost of our variable rate liabilities increasing during a period of rising interest rates. The primary instruments that we use are interest rate swaps, options to enter into interest rate swaps ("swaptions"), U.S. Treasury securities and U.S. Treasury futures contracts. We also use forward contracts in the Agency RMBS "to-be-announced" market, or TBA securities, to invest in and finance Agency securities and to periodically reduce our exposure to Agency RMBS. We account for derivative instruments in accordance with ASC Topic 815, Derivatives and Hedging ("ASC 815"). ASC 815 requires an entity to recognize all derivatives as either assets or liabilities in our accompanying consolidated balance sheets and to measure those instruments at fair value. None of our derivative instruments have been designated as hedging instruments for accounting purposes under the provisions of ASC 815, consequently changes in the fair value of our derivative instruments are reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with the counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. Derivative instruments in a gain position are reported as derivative assets at fair value and derivative instruments in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Changes in fair value of derivative instruments and periodic settlements related to our derivative instruments are recorded in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. Interest rate swap agreements We use interest rate swaps to economically hedge the variable cash flows associated with our borrowings made under repurchase agreements. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate ("payer swaps") based on a short-term benchmark rate, such as the Secured Overnight Financing Rate ("SOFR"), Overnight Index Swap Rate ("OIS") or three-month London Interbank Offered Rate ("LIBOR"). Our interest rate swaps typically have terms from one to 10 years but may extend up to 20 years or more. Our interest rate swaps are centrally cleared through a registered commodities exchange. The clearing exchange requires that we post an "initial margin" amount determined by the exchange, which is generally intended to be set at a level sufficient to protect the exchange from the interest rate swap's maximum estimated single-day price movement. We also exchange daily settlements of "variation margin" based upon changes in fair value, as measured by the exchange. Pursuant to rules governing central clearing activities, we recognize variation margin settlements as a direct reduction of the carrying value of the interest rate swap asset or liability. Interest rate swaptions We purchase interest rate swaptions to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. Interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay and receive interest rates in the future. Our interest rate swaption agreements are not subject to central clearing. The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. The difference between the premium paid and the fair value of the swaption is reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid. If we sell or exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the cash or the fair value of the underlying interest rate swap and the premium paid. TBA securities A TBA security is a forward contract for the purchase or sale of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS to be delivered into the contract are not known until shortly before the settlement date. We may choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting TBA position, net settling the offsetting positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date (together referred to as a "dollar roll transaction"). The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to equivalent securities settling in the current month. This difference, or "price drop," is the economic equivalent of interest income on the underlying Agency securities, less an implied funding cost, over the forward settlement period (referred to as "dollar roll income"). Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. We account for TBA contracts as derivative instruments since either the TBA contracts do not settle in the shortest period of time possible or we cannot assert that it is probable at inception and throughout the term of the TBA contract that we will physically settle the contract on the settlement date. We account for TBA dollar roll transactions as a series of derivative transactions. U.S. Treasury securities We use U.S. Treasury securities and U.S. Treasury futures contracts to mitigate the potential impact of changes in interest rates on the performance of our portfolio. We borrow U.S. Treasury securities under reverse repurchase agreements to cover short sales of U.S. Treasury securities. We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on our accompanying consolidated balance sheets based on the value of the underlying U.S. Treasury security as of the reporting date. Gains and losses associated with U.S. Treasury securities and U.S. Treasury futures contracts are recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Fair Value Measurements We determine the fair value of financial instruments based on our estimate of the price that would be received to sell the asset or paid to transfer the liability in an orderly transaction between market participants at the measurement date. We utilize a three-level valuation hierarchy for disclosure of fair value measurements based upon the transparency of inputs to the valuation of the instrument as of the measurement date. We categorize a financial instrument within the hierarchy based upon the lowest level of input that is significant to the fair value measurement. The three levels of valuation hierarchy are defined as follows: •Level 1 Inputs —Quoted prices (unadjusted) for identical unrestricted assets and liabilities in active markets that are accessible at the measurement date. •Level 2 Inputs —Quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. •Level 3 Inputs —Instruments with primarily unobservable market data that cannot be corroborated. The majority of our financial instruments are classified as Level 2 inputs. The availability of observable inputs can be affected by a wide variety of factors, including the type of instrument, whether the instrument is new and not yet established in the marketplace and other characteristics particular to the instrument. We typically obtain price estimates from multiple third- party pricing sources, such as pricing services and dealers, or, if applicable, the registered clearing exchange. We make inquiries of third-party pricing sources to understand the significant inputs and assumptions they used to determine their prices and that they are derived from orderly transactions, particularly during periods of elevated market turbulence and reduced market liquidity. We also review third-party price estimates and perform procedures to validate their reasonableness, including an analysis of the range of estimates for each position, comparison to recent trade activity for similar securities and for consistency with market conditions observed as of the measurement date. While we do not adjust prices we obtain from pricing sources, we will exclude prices for securities from our estimation of fair value if we determine based on our validation procedures and our market knowledge and expertise that the price is significantly different from what observable market data would indicate and we cannot obtain an understanding from the third-party source as to the significant inputs used to determine the price. The following is a description of the valuation methodologies used for instruments measured at fair value on a recurring basis classified as Level 2 inputs. These instruments trade in active markets such that participants transact with sufficient frequency and volume to provide transparent pricing information on an ongoing basis. The liquidity of these markets and the similarity of our securities and derivative instruments to those actively traded enable our pricing sources and us to observe quoted prices in the market and utilize those prices as a basis for formulating fair value measurements. Investment securities - are valued based on prices obtained from multiple third-party pricing sources. The pricing sources utilize various valuation approaches, including market and income approaches. For Agency RMBS, the pricing sources primarily utilize a matrix pricing technique that interpolates the estimated fair value based on observed quoted prices for forward contracts in the Agency RMBS "to-be-announced" market ("TBA securities") of the same coupon, maturity and issuer, adjusted to reflect the specific characteristics of the pool of mortgages underlying the Agency security, such as maximum loan balance, loan vintage, loan-to-value ratio, geography and other characteristics as may be appropriate. For other investment securities, the pricing sources primarily utilize discounted cash flow model-derived pricing techniques to estimate the fair value. Such models incorporate market-based discount rate assumptions based on observable inputs such as recent trading activity, credit data, volatility statistics, benchmark interest rate curves, spread measurements to benchmark curves and other market data that are current as of the measurement date and may include certain unobservable inputs, such as assumptions of future levels of prepayment, defaults and loss severities. TBA securities - are valued using prices obtained from third-party pricing sources based on pricing models that reference recent trading activity. Interest rate swaps - are valued using the daily settlement price, or fair value, determined by the clearing exchange based on a pricing model that references observable market inputs, including current benchmark rates and the forward yield curve. Interest rate swaptions - are valued using prices obtained from the counterparty and other third-party pricing models. The pricing models are based on the value of the future interest rate swap that we have the option to enter into as well as the remaining length of time that we have to exercise the option based on observable market inputs, adjusted for non-performance risk, if any. U.S. Treasury securities and futures are valued based on quoted prices for identical instruments in active markets and are classified as Level 1 assets. None of our financial instruments are classified as Level 3 inputs. Recent Accounting Pronouncements We consider the applicability and impact of all ASUs issued by the FASB. There are no unadopted ASUs that are expected to have a significant impact on our consolidated financial statements when adopted or other recently adopted ASUs that had a significant impact on our consolidated financial statements upon adoption.
Reverse Repurchase Agreements Policy [Policy Text Block]	Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivative Instruments below). We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on the balance sheet based on the value of the underlying borrowed securities as of the reporting date. We may also enter into reverse repurchase agreements to earn a yield on excess cash balances. The securities received as collateral in connection with our reverse repurchase agreements mitigate our credit risk exposure to counterparties. Our reverse repurchase agreements typically have maturities of 30 days or less.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements We consider the applicability and impact of all ASUs issued by the FASB. There are no unadopted ASUs that are expected to have a significant impact on our consolidated financial statements when adopted or other recently adopted ASUs that had a significant impact on our consolidated financial statements upon adoption.
Investment Securities	Investment Securities Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") guaranteed by the Federal National Mortgage Association ("Fannie Mae"), Federal Home Loan Mortgage Corporation ("Freddie Mac," and together with Fannie Mae, the "GSEs") or the Government National Mortgage Association ("Ginnie Mae"). CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third-party market participants, that synthetically transfer a portion of the risk associated with credit losses within pools of conventional residential mortgage loans from the GSEs and/or third parties to private investors. Unlike Agency RMBS, full repayment of the original principal balance of CRT securities is not guaranteed by a GSE or U.S. Government agency; rather, "credit risk transfer" is achieved by writing down the outstanding principal balance of the CRT securities if credit losses on a related pool of loans exceed certain thresholds. By reducing the amount that they are obligated to repay to holders of CRT securities, the GSEs and/or other third parties offset credit losses on the related loans. Non-Agency RMBS and CMBS (together, "Non-Agency MBS") are backed by residential and commercial mortgage loans, respectively, packaged and securitized by a private institution, such as a commercial bank. Non-Agency MBS typically benefit from credit enhancements derived from structural elements, such as subordination, overcollateralization or insurance, but nonetheless carry a higher level of credit exposure than Agency RMBS. All of our securities are reported at fair value on our consolidated balance sheet. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities, requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for securities pursuant to ASC Topic 825, Financial Instruments. Prior to fiscal year 2017, we primarily designated our investment securities as available-for-sale. On January 1, 2017, we began electing the fair value option of accounting for all investment securities newly acquired after such date. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income ("OCI"), whereas unrealized gains and losses on securities for which we elected the fair value option, or are classified as trading, are reported in net income through other gain (loss). Upon the sale of a security designated as available-for-sale, we determine the cost of the security and the amount of unrealized gain or loss to reclassify out of accumulated OCI into earnings based on the specific identification method. In our view, the election of the fair value option simplifies the accounting for investment securities and more appropriately reflects the results of our operations for a reporting period by presenting the fair value changes for these assets in a manner consistent with the presentation and timing of the fair value changes for our derivative instruments. We generally recognize gains or losses through net income on available-for-sale securities only if the security is sold; however, if the fair value of a security declines below its amortized cost and we determine that it is more likely than not that we will incur a realized loss on the security when we sell the asset, we will recognize the difference between the amortized cost and the fair value in net income as a component of other gain (loss). Since all of our available-for-sale designated securities consist of Agency RMBS, we do not have an allowance for credit losses. We have not recognized impairment losses on our available-for-sale securities through net income for the periods presented in our consolidated financial statements.
Interest Income	Interest Income Interest income is accrued based on the outstanding principal amount of the investment securities and their contractual terms. Premiums or discounts associated with the purchase of Agency RMBS and non-Agency MBS of high credit quality are amortized or accreted into interest income, respectively, over the projected lives of the securities, including contractual payments and estimated prepayments, using the effective interest method in accordance with ASC Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs. We estimate long-term prepayment speeds of our mortgage securities using a third-party service and market data. The third-party service provider estimates prepayment speeds using models that incorporate the forward yield curve, primary to secondary mortgage rate spreads, current mortgage rates, mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, interest rate volatility and other factors. We review the prepayment speeds estimated by the third-party service for reasonableness with consideration given to both historical prepayment speeds and current market conditions. If based on our assessment, we believe that the third-party model does not fully reflect our expectations of the current prepayment landscape, such as during periods of elevated market uncertainty or unique market conditions, we may make adjustments to the models. We review our actual and anticipated prepayment experience on at least a quarterly basis and effective yields are recalculated when differences arise between (i) our previous estimate of future prepayments and (ii) actual prepayments to date and our current estimate of future prepayments. We are required to record an adjustment in the current period to premium amortization / discount accretion for the cumulative effect of the difference in the effective yields as if the recalculated yield had been in place as of the security's acquisition date through the reporting date. At the time we purchase CRT securities and non-Agency MBS that are not of high credit quality, we determine an effective yield based on our estimate of the timing and amount of future cash flows and our cost basis. Our initial cash flow estimates for these investments are based on our observations of current information and events and include assumptions related to interest rates, prepayment rates and the impact of default and severity rates on the timing and amount of credit losses. On at least a quarterly basis, we review the estimated cash flows and make appropriate adjustments based on inputs and analysis received from external sources, internal models, and our judgment regarding such inputs and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment adjusted for credit impairments, if any.
Repurchase and Resale Agreements Policy [Policy Text Block]	Repurchase Agreements We finance the acquisition of securities for our investment portfolio primarily through repurchase agreements with financial institutions. Repurchase arrangements involve the sale and a simultaneous agreement to repurchase the transferred assets at a future date. We maintain a beneficial interest in the specific securities pledged during the term of each repurchase arrangement and we receive the related principal and interest payments. Pursuant to ASC Topic 860, Transfers and Servicing, we account for repurchase agreements as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest. Our repurchase agreements typically have maturities of less than one year but may extend up to five years or more.
Derivative Instruments	Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate, prepayment, extension and liquidity risks. The objective of our risk management strategy is to reduce fluctuations in net book value over a range of interest rate scenarios. In particular, we attempt to mitigate the risk of the cost of our variable rate liabilities increasing during a period of rising interest rates. The primary instruments that we use are interest rate swaps, options to enter into interest rate swaps ("swaptions"), U.S. Treasury securities and U.S. Treasury futures contracts. We also use forward contracts in the Agency RMBS "to-be-announced" market, or TBA securities, to invest in and finance Agency securities and to periodically reduce our exposure to Agency RMBS. We account for derivative instruments in accordance with ASC Topic 815, Derivatives and Hedging ("ASC 815"). ASC 815 requires an entity to recognize all derivatives as either assets or liabilities in our accompanying consolidated balance sheets and to measure those instruments at fair value. None of our derivative instruments have been designated as hedging instruments for accounting purposes under the provisions of ASC 815, consequently changes in the fair value of our derivative instruments are reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with the counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. Derivative instruments in a gain position are reported as derivative assets at fair value and derivative instruments in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Changes in fair value of derivative instruments and periodic settlements related to our derivative instruments are recorded in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. Interest rate swap agreements We use interest rate swaps to economically hedge the variable cash flows associated with our borrowings made under repurchase agreements. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate ("payer swaps") based on a short-term benchmark rate, such as the Secured Overnight Financing Rate ("SOFR"), Overnight Index Swap Rate ("OIS") or three-month London Interbank Offered Rate ("LIBOR"). Our interest rate swaps typically have terms from one to 10 years but may extend up to 20 years or more. Our interest rate swaps are centrally cleared through a registered commodities exchange. The clearing exchange requires that we post an "initial margin" amount determined by the exchange, which is generally intended to be set at a level sufficient to protect the exchange from the interest rate swap's maximum estimated single-day price movement. We also exchange daily settlements of "variation margin" based upon changes in fair value, as measured by the exchange. Pursuant to rules governing central clearing activities, we recognize variation margin settlements as a direct reduction of the carrying value of the interest rate swap asset or liability. Interest rate swaptions We purchase interest rate swaptions to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. Interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay and receive interest rates in the future. Our interest rate swaption agreements are not subject to central clearing. The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. The difference between the premium paid and the fair value of the swaption is reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid. If we sell or exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the cash or the fair value of the underlying interest rate swap and the premium paid. TBA securities A TBA security is a forward contract for the purchase or sale of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS to be delivered into the contract are not known until shortly before the settlement date. We may choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting TBA position, net settling the offsetting positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date (together referred to as a "dollar roll transaction"). The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to equivalent securities settling in the current month. This difference, or "price drop," is the economic equivalent of interest income on the underlying Agency securities, less an implied funding cost, over the forward settlement period (referred to as "dollar roll income"). Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. We account for TBA contracts as derivative instruments since either the TBA contracts do not settle in the shortest period of time possible or we cannot assert that it is probable at inception and throughout the term of the TBA contract that we will physically settle the contract on the settlement date. We account for TBA dollar roll transactions as a series of derivative transactions. U.S. Treasury securities We use U.S. Treasury securities and U.S. Treasury futures contracts to mitigate the potential impact of changes in interest rates on the performance of our portfolio. We borrow U.S. Treasury securities under reverse repurchase agreements to cover short sales of U.S. Treasury securities. We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on our accompanying consolidated balance sheets based on the value of the underlying U.S. Treasury security as of the reporting date. Gains and losses associated with U.S. Treasury securities and U.S. Treasury futures contracts are recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income.
Fair Value Measurement, Policy	Fair Value Measurements We determine the fair value of financial instruments based on our estimate of the price that would be received to sell the asset or paid to transfer the liability in an orderly transaction between market participants at the measurement date. We utilize a three-level valuation hierarchy for disclosure of fair value measurements based upon the transparency of inputs to the valuation of the instrument as of the measurement date. We categorize a financial instrument within the hierarchy based upon the lowest level of input that is significant to the fair value measurement. The three levels of valuation hierarchy are defined as follows: •Level 1 Inputs —Quoted prices (unadjusted) for identical unrestricted assets and liabilities in active markets that are accessible at the measurement date. •Level 2 Inputs —Quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. •Level 3 Inputs —Instruments with primarily unobservable market data that cannot be corroborated. The majority of our financial instruments are classified as Level 2 inputs. The availability of observable inputs can be affected by a wide variety of factors, including the type of instrument, whether the instrument is new and not yet established in the marketplace and other characteristics particular to the instrument. We typically obtain price estimates from multiple third- party pricing sources, such as pricing services and dealers, or, if applicable, the registered clearing exchange. We make inquiries of third-party pricing sources to understand the significant inputs and assumptions they used to determine their prices and that they are derived from orderly transactions, particularly during periods of elevated market turbulence and reduced market liquidity. We also review third-party price estimates and perform procedures to validate their reasonableness, including an analysis of the range of estimates for each position, comparison to recent trade activity for similar securities and for consistency with market conditions observed as of the measurement date. While we do not adjust prices we obtain from pricing sources, we will exclude prices for securities from our estimation of fair value if we determine based on our validation procedures and our market knowledge and expertise that the price is significantly different from what observable market data would indicate and we cannot obtain an understanding from the third-party source as to the significant inputs used to determine the price. The following is a description of the valuation methodologies used for instruments measured at fair value on a recurring basis classified as Level 2 inputs. These instruments trade in active markets such that participants transact with sufficient frequency and volume to provide transparent pricing information on an ongoing basis. The liquidity of these markets and the similarity of our securities and derivative instruments to those actively traded enable our pricing sources and us to observe quoted prices in the market and utilize those prices as a basis for formulating fair value measurements. Investment securities - are valued based on prices obtained from multiple third-party pricing sources. The pricing sources utilize various valuation approaches, including market and income approaches. For Agency RMBS, the pricing sources primarily utilize a matrix pricing technique that interpolates the estimated fair value based on observed quoted prices for forward contracts in the Agency RMBS "to-be-announced" market ("TBA securities") of the same coupon, maturity and issuer, adjusted to reflect the specific characteristics of the pool of mortgages underlying the Agency security, such as maximum loan balance, loan vintage, loan-to-value ratio, geography and other characteristics as may be appropriate. For other investment securities, the pricing sources primarily utilize discounted cash flow model-derived pricing techniques to estimate the fair value. Such models incorporate market-based discount rate assumptions based on observable inputs such as recent trading activity, credit data, volatility statistics, benchmark interest rate curves, spread measurements to benchmark curves and other market data that are current as of the measurement date and may include certain unobservable inputs, such as assumptions of future levels of prepayment, defaults and loss severities. TBA securities - are valued using prices obtained from third-party pricing sources based on pricing models that reference recent trading activity. Interest rate swaps - are valued using the daily settlement price, or fair value, determined by the clearing exchange based on a pricing model that references observable market inputs, including current benchmark rates and the forward yield curve. Interest rate swaptions - are valued using prices obtained from the counterparty and other third-party pricing models. The pricing models are based on the value of the future interest rate swap that we have the option to enter into as well as the remaining length of time that we have to exercise the option based on observable market inputs, adjusted for non-performance risk, if any. U.S. Treasury securities and futures are valued based on quoted prices for identical instruments in active markets and are classified as Level 1 assets. None of our financial instruments are classified as Level 3 inputs.

Stockholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax	$ (77)	$ 203	$ (314)	$ 667
Agency Securities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning OCI Balance	482	561	719	97
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax	(63)	242	(282)	707
Amounts reclassified from accumulated OCI	(14)	(39)	(32)	(40)
Ending OCI Balance	$ 405	$ 764	$ 405	$ 764

Derivative and Other Hedging Instruments (US Treasury Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
U.S. Treasury securities, net	$ (10,523)		$ (11,727)
Weighted Average Yield Percentage	2.42%		2.33%
7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	$ (1,083)		$ (1,083)
At Par Value [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(10,496)		(11,288)
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(26,567)	$ (24,518)	(30,364)	$ (19,760)	$ (20,279)	$ (7,322)
Derivative, Forward Settlement Value	(27,307)		(31,204)
Derivative Asset, Fair Value, Gross Asset	(27,386)		(31,479)
Derivative, Fair Value, Net	79		275
5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(1,665)		(425)
10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(7,748)		(9,780)
10 Year Maturity [Member] \| US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	(6)		(2)
Short [Member] \| US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(10,893)	$ (15,527)	(11,287)	$ (7,247)	$ (4,245)	$ (9,224)
Short [Member] \| 10 Year Maturity [Member] \| US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,500)		(1,000)
Derivative, Forward Settlement Value	(1,982)		(1,379)
Derivative Asset, Fair Value, Gross Asset	(1,988)		(1,381)
Fair Value Hedging [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(10,523)		(11,727)
Fair Value Hedging [Member] \| 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(1,049)		(1,089)
Fair Value Hedging [Member] \| 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(1,631)		(425)
Fair Value Hedging [Member] \| 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(7,843)		(10,213)
Fair Value Hedging [Member] \| Long [Member]
Derivative [Line Items]
U.S. Treasury securities, net	397
At Cost Basis [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(10,460)		(11,368)
At Cost Basis [Member] \| 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(1,072)		(1,081)
At Cost Basis [Member] \| 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(1,648)		(425)
At Cost Basis [Member] \| 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	$ (7,740)		$ (9,862)
US Treasury Securities [Member] \| Short [Member]
Derivative [Line Items]
Weighted Average Yield Percentage	1.30%		1.20%
US Treasury Securities [Member] \| Long [Member]
Derivative [Line Items]
Weighted Average Yield Percentage	0.98%

Pledged Assets (Offsetting Assets and Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Offsetting Assets and Liabilities [Line Items]
Collateral Received	$ (5,056)
Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	12,360	$ 12,139
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	12,360	12,139
Financial Instruments	(7,224)	(6,522)
Collateral Received		(5,328)
Net Amount	80	289
Assets [Member] \| ERROR in label resolution.
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	294	116
Net Amounts of Assets Presented in the Consolidated Balance Sheets	294	116
Financial Instruments	0	0
Collateral Received	(293)	(105)
Net Amount	1	11
Assets [Member] \| TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	87	275
Net Amounts of Assets Presented in the Consolidated Balance Sheets	87	275
Financial Instruments	(8)	0
Net Amount	79	275
Assets [Member] \| Reverse Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Net Amount	0	3
Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	48,745	52,366
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	48,745	52,366
Financial Instruments	(7,224)	(6,522)
Collateral Received	(41,520)	(45,844)
Net Amount	1
Liability [Member] \| Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Net Amount	1	0
Liability [Member] \| ERROR in label resolution.
Offsetting Assets and Liabilities [Line Items]
Net Amount		0
Liability [Member] \| TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	8
Net Amounts of Assets Presented in the Consolidated Balance Sheets	8
Financial Instruments	(8)
Collateral Received	0
Net Amount	0
Reverse Repurchase Agreements [Member] \| Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	11,979	11,748
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	11,979	11,748
Financial Instruments	(7,216)	(6,522)
Collateral Received	(4,763)	(5,223)
Repurchase Agreements [Member] \| Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	48,737	52,366
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	48,737	52,366
Financial Instruments	(7,216)	(6,522)
Collateral Received	$ (41,520)	$ (45,844)

Derivative and Other Hedging Instruments (Summary Of Outstanding Interest Rate Swaps) (Details) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($) month	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) month	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Interest Rate Swaps Linked to Overnight Index Swap Rate	26.00%			26.00%		29.00%
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (680)		$ (237)	$ 763	$ (3,417)
Interest Rate Swaps Linked to Secured Overnight Financing Rate	74.00%			74.00%		71.00%
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (313)		(14)	$ 74	(148)
Notional Amount	$ 11,450			$ 11,450		$ 10,400
Average Fixed Pay Rate	1.77%			1.77%		1.84%
Options At Cost		$ 237		$ 291
Interest Rate Derivatives, at Fair Value, Net	$ 294			$ 294		$ 116
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration \| month		15		19
Average Maturity (Years)		9 years 6 months		9 years 6 months
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(400)		$ (379)	$ 724	$ (3,174)
Notional Amount	$ 49,725			$ 49,725		$ 43,225
Average Fixed Pay Rate	0.18%			0.18%		0.15%
Average Receive Rate	0.06%			0.06%		0.08%
Average Maturity (Years)		5 years 1 month 6 days		4 years 4 months 24 days
Less Than or Equal to One Year [Member] \| Interest Rate Swaption [Member]
Notional Amount	$ 4,200			$ 4,200		$ 5,900
Average Fixed Pay Rate	1.77%			1.77%		2.17%
Options At Cost		$ 123		$ 101
Interest Rate Derivatives, at Fair Value, Net	$ 55			$ 55		$ 15
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration \| month		5		5
Average Maturity (Years)		9 years 2 months 12 days		8 years 9 months 18 days
Greater Than One Year and Less Than or Equal to Two Years [Member] \| Interest Rate Swaption [Member]
Notional Amount	$ 3,250			$ 3,250		$ 2,000
Average Fixed Pay Rate	1.41%			1.41%		1.38%
Options At Cost		$ 41		$ 80
Interest Rate Derivatives, at Fair Value, Net	$ 117			$ 117		$ 33
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration \| month		20		20
Average Maturity (Years)		10 years		10 years
Greater Than Two Years and Less Than or Equal to Three Years [Member] \| Interest Rate Swaption [Member]
Notional Amount	$ 4,000			$ 4,000		$ 2,250
Average Fixed Pay Rate	2.07%			2.07%		1.40%
Options At Cost		$ 65		$ 110
Interest Rate Derivatives, at Fair Value, Net	$ 122			$ 122		$ 60
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration \| month		33		32
Average Maturity (Years)		10 years		10 years
Greater Than One Year and Less Than or Equal to Three Years [Member] \| Interest Rate Swap [Member]
Notional Amount	$ 16,000			$ 16,000		$ 8,750
Average Fixed Pay Rate	0.11%			0.11%		0.04%
Average Receive Rate	0.06%			0.06%		0.08%
Average Maturity (Years)		2 years 4 months 24 days		2 years 3 months 18 days
Greater Than Three Years and Less Than or Equal to Five Years [Member] \| Interest Rate Swap [Member]
Notional Amount	$ 18,500			$ 18,500		$ 17,000
Average Fixed Pay Rate	0.13%			0.13%		0.10%
Average Receive Rate	0.06%			0.06%		0.08%
Average Maturity (Years)		4 years 1 month 6 days		3 years 10 months 24 days
Greater Than Five Years and Less than or Equal to Seven Years [Member] \| Interest Rate Swap [Member]
Notional Amount	$ 7,050			$ 7,050		$ 9,800
Average Fixed Pay Rate	0.21%			0.21%		0.21%
Average Receive Rate	0.05%			0.05%		0.08%
Average Maturity (Years)		5 years 9 months 18 days		5 years 6 months
Greater Than Seven Years and Less than or Equal to Ten Years [Member] \| Interest Rate Swap [Member]
Notional Amount	$ 6,700			$ 6,700		$ 6,200
Average Fixed Pay Rate	0.36%			0.36%		0.28%
Average Receive Rate	0.05%			0.05%		0.07%
Average Maturity (Years)		8 years 6 months		8 years 1 month 6 days
Greater Than Ten Years [Member] \| Interest Rate Swap [Member]
Notional Amount	$ 1,475			$ 1,475		$ 1,475
Average Fixed Pay Rate	0.47%			0.47%		0.47%
Average Receive Rate	0.06%			0.06%		0.07%
Average Maturity (Years)		14 years 2 months 12 days		13 years 8 months 12 days
Greater Than Three Years and Less Than or Equal to Four Years \| Interest Rate Swaption [Member]
Notional Amount						$ 250
Average Fixed Pay Rate						1.43%
Options At Cost		$ 8
Interest Rate Derivatives, at Fair Value, Net						$ 8
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration \| month		40
Average Maturity (Years)		10 years

Investment Securities (Summary Of Agency Securities Estimated Weighted Average Life Classifications) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Agency securities classified as available for sale, Fair value	$ 59,799	$ 66,414
Agency securities classified as available for sale, Amortized cost	$ 58,379	$ 63,701
Weighted Average Coupon	3.19%	3.39%
Weighted Average Yield	2.42%	2.33%
Less Than or Equal to Three Years [Member]
Fair Value	$ 1,407	$ 3,642
Amortized Cost	$ 1,370	$ 3,569
Weighted Average Coupon	3.59%	3.56%
Weighted Average Yield	2.69%	2.15%
Greater Than Three Years and Less Than or Equal to Five Years [Member]
Fair Value	$ 15,366	$ 47,740
Amortized Cost	$ 14,905	$ 45,578
Weighted Average Coupon	3.62%	3.54%
Weighted Average Yield	2.49%	2.42%
Greater Than Five Years [Member]
Fair Value	$ 40,176	$ 15,019
Amortized Cost	$ 39,276	$ 14,541
Weighted Average Coupon	3.07%	2.87%
Weighted Average Yield	2.41%	2.08%
Greater Than Ten Years [Member]
Fair Value	$ 2,850	$ 13
Amortized Cost	$ 2,828	$ 13
Weighted Average Coupon	2.32%	5.56%
Weighted Average Yield	2.09%	3.59%

Investment Securities (Summary Of Net Gain From Sale Of Agency Securities) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Cost of Sale of Fair Value Option Securities	$ (8,659)	$ (4,472)	$ (14,523)	$ (53,912)
Cost of Sale of Investment Securities	(12,810)	(5,750)	(19,167)	(55,345)
Proceeds from agency MBS sold			10,172	16,206
Net gain (loss) on sale of investment securities	25	153	12	647
Available-for-sale Securities [Member]
Agency MBS sold, at cost	(4,151)	(1,278)	(4,644)	(1,433)
Proceeds from agency MBS sold	4,165	1,317	4,676	1,473
Net gain (loss) on sale of investment securities		39		40
Gross gain on sale of investment securities	14	39	32	40
Gross loss on sale of investment securities	0	0	0	0
Securities Remeasured at Fair Value [Member]
Proceeds from agency MBS sold	8,670	4,586	14,503	54,519
Net gain (loss) on sale of investment securities		114		607
Gross gain on sale of investment securities	48	129	97	696
Gross loss on sale of investment securities	(37)	(15)	(117)	(89)
Securities (Assets) [Member]
Proceeds from agency MBS sold	12,835	5,903	19,179	55,992
Net gain (loss) on sale of investment securities	25	153	12	647
Gross gain on sale of investment securities	62	168	129	736
Gross loss on sale of investment securities	(37)	$ (15)	(117)	$ (89)
Cost and Proceeds of Investment Securities [Member] \| Available-for-sale Securities [Member]
Net gain (loss) on sale of investment securities	14		32
Cost and Proceeds of Investment Securities [Member] \| Securities Remeasured at Fair Value [Member]
Net gain (loss) on sale of investment securities	$ 11		(20)
Gross Gain & Loss of Investment Securities [Member] \| Available-for-sale Securities [Member]
Net gain (loss) on sale of investment securities			32
Gross Gain & Loss of Investment Securities [Member] \| Securities Remeasured at Fair Value [Member]
Net gain (loss) on sale of investment securities			$ (20)

Investment Securities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure		$ 59,800	$ 66,400
Weighted average expected constant prepayment rate	17.60%	11.60%
Debt, at fair value		$ (148)	(177)
Agency Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Unamortized premium balance		2,100	2,400
TBA securities Fifteen Year and Thirty Year Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Net long TBA position, at fair value		27,400	31,500
TBA, net carrying value		79	275
Forward Settling non-Agency Securities
Debt Securities, Available-for-sale [Line Items]
Net long TBA position, at fair value		$ 300	$ 0

Summary of Significant Accounting Policies Variable Interest Entities (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Other Long-term Debt	$ 148	$ 177

Stockholders' Equity (Follow-On Equity Offerings) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Class of Stock [Line Items]
Stock Issued During Period, Value, New Issues	$ 439

Pledged Assets (Assets Pledged as Collateral) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	$ 50,319	$ 54,314
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repurchase Agreements	98	119
Accrued interest on pledged securities	131	150
Restricted cash	623	1,307
Total Fair Value of Securities Pledged and Accrued Interest	52,814
Total Fair Value Of Agency Securities Pledged And Accrued Interest		56,689
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	49,044	53,401
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	483	365
Accrued interest on pledged securities		1
Restricted cash	604	890
Total Fair Value of Securities Pledged and Accrued Interest	1,088
Total Fair Value Of Agency Securities Pledged And Accrued Interest		1,256
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Accrued interest on pledged securities	128	147
Total Fair Value of Securities Pledged and Accrued Interest	50,803
Total Fair Value Of Agency Securities Pledged And Accrued Interest		54,878
Variable Interest Entity, Primary Beneficiary [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	245	295
Accrued interest on pledged securities	1	1
Total Fair Value of Securities Pledged and Accrued Interest	246
Total Fair Value Of Agency Securities Pledged And Accrued Interest		296
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	404	258
Accrued interest on pledged securities	1	1
Total Fair Value of Securities Pledged and Accrued Interest	677
Total Fair Value Of Agency Securities Pledged And Accrued Interest		259
Includes Sold But Not Yet Settled Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	50,176	54,319
Credit Risk Transfer Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	502	455
Credit Risk Transfer Securities [Member] \| Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	502	455
Credit Risk Transfer Securities [Member] \| Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	0	0
Non-Agency [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	377	458
Non-Agency [Member] \| Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	377	458
Non-Agency [Member] \| Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	0	0
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	1,005
US Treasury Securities [Member] \| Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	272
US Treasury Securities [Member] \| Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	733
US Treasury Securities [Member] \| Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	0
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Accrued interest on pledged securities	1
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash	19	417
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash	0	0
Excluding Cash Received [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash	$ 623	$ 1,307

Repurchase Agreements And Reverse Repurchase Agreements

6 Months Ended

Jun. 30, 2021

Disclosure of Repurchase Agreements [Abstract]

Repurchase Agreements And Other Debt

Repurchase Agreements and Reverse Repurchase Agreements

Repurchase Agreements

We pledge our securities as collateral under our borrowings structured as repurchase agreements with financial institutions. Amounts available to be borrowed are dependent upon the fair value of the securities pledged as collateral, which fluctuates with changes in interest rates, type of security and liquidity conditions within the banking, mortgage finance and real estate industries. If the fair value of our pledged securities declines, lenders will typically require us to post additional collateral or pay down borrowings to re-establish agreed upon collateral requirements, referred to as "margin calls." Similarly, if the fair value of our pledged securities increases, lenders may release collateral back to us. As of June 30, 2021, we had met all margin call requirements. For additional information regarding our pledged assets, please refer to Note 6.

As of June 30, 2021 and December 31, 2020, we had $48.7 billion and $52.4 billion, respectively, of repurchase agreements outstanding used to fund our investment portfolio and temporary holdings of U.S. Treasury securities. The terms and conditions of our repurchase agreements are typically negotiated on a transaction-by-transaction basis. Our repurchase agreements with original maturities greater than one year may have floating interest rates based on an index plus or minus a

fixed spread. The following table summarizes our borrowings under repurchase agreements by their remaining maturities as of June 30, 2021 and December 31, 2020 (dollars in millions):


	June 30, 2021					December 31, 2020
Remaining Maturity	Repurchase Agreements		Weighted Average Interest Rate		Weighted Average Days to Maturity	Repurchase Agreements		Weighted Average Interest Rate		Weighted Average Days to Maturity
Agency repo:
≤ 1 month	$	31,093	0.10	%	11	$	29,505	0.22	%	12
> 1 to ≤ 3 months	8,794		0.15	%	67	13,434		0.27	%	57
> 3 to ≤ 6 months	1,662		0.12	%	148	7,317		0.28	%	142
> 6 to ≤ 9 months	5,916		0.15	%	199	660		0.24	%	208
> 9 to ≤ 12 months	875		0.18	%	303	1,450		0.15	%	354


Total Agency repo	48,340		0.11	%	54	52,366		0.24	%	54
U.S. Treasury repo:
> 1 day to ≤ 1 month	397		0.02	%	1	—		—	%	—
Total	$	48,737	0.11	%	54	$	52,366	0.24	%	54

As of June 30, 2021 and December 31, 2020, $7.4 billion and $11.2 billion, respectively, of our repurchase agreements had an overnight maturity of one business day and none of our repurchase agreements were due on demand. As of June 30, 2021, we had $8.3 billion of forward commitments to enter into repurchase agreements with a weighted average forward start date of 2 days and a weighted average interest rate of 0.06%. As of December 31, 2020, we had $2.9 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 4 days and a weighted average interest rate of 0.12%. As of June 30, 2021 and December 31, 2020, 44% and 47%, respectively, of our repurchase agreement funding was sourced through our wholly-owned captive broker-dealer subsidiary, Bethesda Securities, LLC ("BES"). Amounts sourced through BES include funding from the General Collateral Finance Repo service ("GCF Repo") offered by the Fixed Income Clearing Corporation ("FICC"), which totaled 43% and 46% of our repurchase agreement funding outstanding as of June 30, 2021 and December 31, 2020, respectively.

During the three and six months ended June 30, 2020, we terminated $3.7 billion of repurchase agreements with a weighted average interest rate of 2.11% and a weighted average remaining maturity of 2.2 years. The terminated agreements were replaced with shorter duration repurchase agreements at lower prevailing market rates. We recognized losses on debt extinguishment of $146 million in other gain (loss), net for the three and six months ended June 30, 2020 associated with the terminated repurchase agreements. We did not terminate any repurchase agreements during the prior year periods.

Reverse Repurchase Agreements

As of June 30, 2021 and December 31, 2020, we had $12.0 billion and $11.7 billion, respectively, of reverse repurchase agreements outstanding used primarily to borrow securities to cover short sales of U.S. Treasury securities, for which we had associated obligations to return borrowed securities at fair value of $10.9 billion and $11.7 billion, respectively. As of June 30, 2021 and December 31, 2020, $2.7 billion and $3.6 billion, respectively, of our reverse repurchase agreements were with the FICC sourced through BES.

Derivative and Other Hedging Instruments (Fair Value Information) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative asset, fair value	$ 381		$ 381			$ 391
Derivative liability, fair value	(14)		(14)			(2)
Derivative assets, at fair value	(381)		(381)			(391)
Derivative Liability	(14)		(14)			(2)
U.S. Treasury securities	397		397			0
U.S. Treasury Securities - short	(10,920)		(10,920)			(11,727)
Total - (short)/long, net	(10,523)		(10,523)			(11,727)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(680)	$ (237)	763	$ (3,417)
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	94,248	75,186	187,584	112,936
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period				(100,498)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	396	220	(530)	913
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	49,725		49,725			43,225
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	0	25,750	7,000	75,725
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	0	(30,150)	(500)	(112,725)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(400)	(379)	724	(3,174)
Interest Rate Swap [Member] \| Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	0		0			0
Interest Rate Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	11,450		11,450			10,400
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	0	0	4,250	2,000
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(1,700)	(200)	(3,200)	(1,500)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(313)	(14)	74	(148)
Interest Rate Swaption [Member] \| Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	294		294			116
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative liability, fair value	(8)		(8)			0
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(92,199)	(75,705)	(191,381)
US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(29)	(8)	32	(112)
US Treasury Securities [Member] \| Fair Value, Recurring [Member] \| Future [Member] \| Fair Value, Inputs, Level 1 [Member]
Derivative [Line Items]
Derivative Liability	(6)		(6)			(2)
TBA and Forward Settling Agency Securities [Member] \| Fair Value, Recurring [Member] \| Purchases Of TBAs And Forward Settling Agency Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative assets, at fair value	(87)		(87)			(275)
Short [Member] \| US Treasury Securities [Member]
Derivative [Line Items]
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	585	4,187	7,846	10,232
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	5,219	1,185	8,240	(12,209)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(333)	(60)	474	(997)
Long [Member] \| US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(1)	4	(11)	101
Debt Securities, Trading, and Equity Securities, FV-NI	397	1,132	397	1,132	$ 0	$ 0	$ 3,569	$ 95
Trading Securities Added During the Period	1,336	550	2,651	7,011
Notional Amount Of Trading Securities Settlement Expiration During The Period	$ (939)	$ (2,987)	$ (2,254)	$ (5,974)

Investment Securities (Summary Of Changes In Accumulated OCI For Available-For-Sale Security) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Unrealized Gains and (Losses), Net	$ (77)	$ 203	$ (314)	$ 667
Agency Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning OCI Balance	482	561	719	97
Unrealized Gains and (Losses), Net	(63)	242	(282)	707
Reversal of Unrealized (Gains) and Losses, Net on Realization	(14)	(39)	(32)	(40)
Ending OCI Balance	$ 405	$ 764	$ 405	$ 764

Income Taxes (Details)	6 Months Ended
Income Taxes (Details)	Jun. 30, 2021
Investments, Owned, Federal Income Tax Note [Line Items]
Required Annual Distribution of Taxable Net Income	90.00%

Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Basis of Presentation Our accompanying consolidated financial statements and related notes have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Article 10 of Regulation S-X. The accompanying consolidated financial statements and related notes are unaudited and include the accounts of all our wholly-owned subsidiaries and variable interest entities for which we are the primary beneficiary. Significant intercompany accounts and transactions have been eliminated. The accompanying consolidated financial statements and related notes should be read in conjunction with the audited consolidated financial statements included in our most recent Annual Report on Form 10-K for the fiscal year ended December 31, 2020. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of income and expenses during the reporting period. In the opinion of management, all adjustments, consisting solely of normal recurring accruals, necessary for the fair presentation of consolidated financial statements for the interim period have been included. The current period’s results of operations are not necessarily indicative of results that ultimately may be achieved for the year. Investment Securities Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") guaranteed by the Federal National Mortgage Association ("Fannie Mae"), Federal Home Loan Mortgage Corporation ("Freddie Mac," and together with Fannie Mae, the "GSEs") or the Government National Mortgage Association ("Ginnie Mae"). CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third-party market participants, that synthetically transfer a portion of the risk associated with credit losses within pools of conventional residential mortgage loans from the GSEs and/or third parties to private investors. Unlike Agency RMBS, full repayment of the original principal balance of CRT securities is not guaranteed by a GSE or U.S. Government agency; rather, "credit risk transfer" is achieved by writing down the outstanding principal balance of the CRT securities if credit losses on a related pool of loans exceed certain thresholds. By reducing the amount that they are obligated to repay to holders of CRT securities, the GSEs and/or other third parties offset credit losses on the related loans. Non-Agency RMBS and CMBS (together, "Non-Agency MBS") are backed by residential and commercial mortgage loans, respectively, packaged and securitized by a private institution, such as a commercial bank. Non-Agency MBS typically benefit from credit enhancements derived from structural elements, such as subordination, overcollateralization or insurance, but nonetheless carry a higher level of credit exposure than Agency RMBS. All of our securities are reported at fair value on our consolidated balance sheet. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities, requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for securities pursuant to ASC Topic 825, Financial Instruments. Prior to fiscal year 2017, we primarily designated our investment securities as available-for-sale. On January 1, 2017, we began electing the fair value option of accounting for all investment securities newly acquired after such date. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income ("OCI"), whereas unrealized gains and losses on securities for which we elected the fair value option, or are classified as trading, are reported in net income through other gain (loss). Upon the sale of a security designated as available-for-sale, we determine the cost of the security and the amount of unrealized gain or loss to reclassify out of accumulated OCI into earnings based on the specific identification method. In our view, the election of the fair value option simplifies the accounting for investment securities and more appropriately reflects the results of our operations for a reporting period by presenting the fair value changes for these assets in a manner consistent with the presentation and timing of the fair value changes for our derivative instruments. We generally recognize gains or losses through net income on available-for-sale securities only if the security is sold; however, if the fair value of a security declines below its amortized cost and we determine that it is more likely than not that we will incur a realized loss on the security when we sell the asset, we will recognize the difference between the amortized cost and the fair value in net income as a component of other gain (loss). Since all of our available-for-sale designated securities consist of Agency RMBS, we do not have an allowance for credit losses. We have not recognized impairment losses on our available-for-sale securities through net income for the periods presented in our consolidated financial statements. Interest Income Interest income is accrued based on the outstanding principal amount of the investment securities and their contractual terms. Premiums or discounts associated with the purchase of Agency RMBS and non-Agency MBS of high credit quality are amortized or accreted into interest income, respectively, over the projected lives of the securities, including contractual payments and estimated prepayments, using the effective interest method in accordance with ASC Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs. We estimate long-term prepayment speeds of our mortgage securities using a third-party service and market data. The third-party service provider estimates prepayment speeds using models that incorporate the forward yield curve, primary to secondary mortgage rate spreads, current mortgage rates, mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, interest rate volatility and other factors. We review the prepayment speeds estimated by the third-party service for reasonableness with consideration given to both historical prepayment speeds and current market conditions. If based on our assessment, we believe that the third-party model does not fully reflect our expectations of the current prepayment landscape, such as during periods of elevated market uncertainty or unique market conditions, we may make adjustments to the models. We review our actual and anticipated prepayment experience on at least a quarterly basis and effective yields are recalculated when differences arise between (i) our previous estimate of future prepayments and (ii) actual prepayments to date and our current estimate of future prepayments. We are required to record an adjustment in the current period to premium amortization / discount accretion for the cumulative effect of the difference in the effective yields as if the recalculated yield had been in place as of the security's acquisition date through the reporting date. At the time we purchase CRT securities and non-Agency MBS that are not of high credit quality, we determine an effective yield based on our estimate of the timing and amount of future cash flows and our cost basis. Our initial cash flow estimates for these investments are based on our observations of current information and events and include assumptions related to interest rates, prepayment rates and the impact of default and severity rates on the timing and amount of credit losses. On at least a quarterly basis, we review the estimated cash flows and make appropriate adjustments based on inputs and analysis received from external sources, internal models, and our judgment regarding such inputs and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment adjusted for credit impairments, if any. Repurchase Agreements We finance the acquisition of securities for our investment portfolio primarily through repurchase agreements with financial institutions. Repurchase arrangements involve the sale and a simultaneous agreement to repurchase the transferred assets at a future date. We maintain a beneficial interest in the specific securities pledged during the term of each repurchase arrangement and we receive the related principal and interest payments. Pursuant to ASC Topic 860, Transfers and Servicing, we account for repurchase agreements as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest. Our repurchase agreements typically have maturities of less than one year but may extend up to five years or more. Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivative Instruments below). We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on the balance sheet based on the value of the underlying borrowed securities as of the reporting date. We may also enter into reverse repurchase agreements to earn a yield on excess cash balances. The securities received as collateral in connection with our reverse repurchase agreements mitigate our credit risk exposure to counterparties. Our reverse repurchase agreements typically have maturities of 30 days or less. Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate, prepayment, extension and liquidity risks. The objective of our risk management strategy is to reduce fluctuations in net book value over a range of interest rate scenarios. In particular, we attempt to mitigate the risk of the cost of our variable rate liabilities increasing during a period of rising interest rates. The primary instruments that we use are interest rate swaps, options to enter into interest rate swaps ("swaptions"), U.S. Treasury securities and U.S. Treasury futures contracts. We also use forward contracts in the Agency RMBS "to-be-announced" market, or TBA securities, to invest in and finance Agency securities and to periodically reduce our exposure to Agency RMBS. We account for derivative instruments in accordance with ASC Topic 815, Derivatives and Hedging ("ASC 815"). ASC 815 requires an entity to recognize all derivatives as either assets or liabilities in our accompanying consolidated balance sheets and to measure those instruments at fair value. None of our derivative instruments have been designated as hedging instruments for accounting purposes under the provisions of ASC 815, consequently changes in the fair value of our derivative instruments are reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with the counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. Derivative instruments in a gain position are reported as derivative assets at fair value and derivative instruments in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Changes in fair value of derivative instruments and periodic settlements related to our derivative instruments are recorded in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. Interest rate swap agreements We use interest rate swaps to economically hedge the variable cash flows associated with our borrowings made under repurchase agreements. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate ("payer swaps") based on a short-term benchmark rate, such as the Secured Overnight Financing Rate ("SOFR"), Overnight Index Swap Rate ("OIS") or three-month London Interbank Offered Rate ("LIBOR"). Our interest rate swaps typically have terms from one to 10 years but may extend up to 20 years or more. Our interest rate swaps are centrally cleared through a registered commodities exchange. The clearing exchange requires that we post an "initial margin" amount determined by the exchange, which is generally intended to be set at a level sufficient to protect the exchange from the interest rate swap's maximum estimated single-day price movement. We also exchange daily settlements of "variation margin" based upon changes in fair value, as measured by the exchange. Pursuant to rules governing central clearing activities, we recognize variation margin settlements as a direct reduction of the carrying value of the interest rate swap asset or liability. Interest rate swaptions We purchase interest rate swaptions to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. Interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay and receive interest rates in the future. Our interest rate swaption agreements are not subject to central clearing. The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. The difference between the premium paid and the fair value of the swaption is reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid. If we sell or exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the cash or the fair value of the underlying interest rate swap and the premium paid. TBA securities A TBA security is a forward contract for the purchase or sale of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS to be delivered into the contract are not known until shortly before the settlement date. We may choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting TBA position, net settling the offsetting positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date (together referred to as a "dollar roll transaction"). The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to equivalent securities settling in the current month. This difference, or "price drop," is the economic equivalent of interest income on the underlying Agency securities, less an implied funding cost, over the forward settlement period (referred to as "dollar roll income"). Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. We account for TBA contracts as derivative instruments since either the TBA contracts do not settle in the shortest period of time possible or we cannot assert that it is probable at inception and throughout the term of the TBA contract that we will physically settle the contract on the settlement date. We account for TBA dollar roll transactions as a series of derivative transactions. U.S. Treasury securities We use U.S. Treasury securities and U.S. Treasury futures contracts to mitigate the potential impact of changes in interest rates on the performance of our portfolio. We borrow U.S. Treasury securities under reverse repurchase agreements to cover short sales of U.S. Treasury securities. We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on our accompanying consolidated balance sheets based on the value of the underlying U.S. Treasury security as of the reporting date. Gains and losses associated with U.S. Treasury securities and U.S. Treasury futures contracts are recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Fair Value Measurements We determine the fair value of financial instruments based on our estimate of the price that would be received to sell the asset or paid to transfer the liability in an orderly transaction between market participants at the measurement date. We utilize a three-level valuation hierarchy for disclosure of fair value measurements based upon the transparency of inputs to the valuation of the instrument as of the measurement date. We categorize a financial instrument within the hierarchy based upon the lowest level of input that is significant to the fair value measurement. The three levels of valuation hierarchy are defined as follows: •Level 1 Inputs —Quoted prices (unadjusted) for identical unrestricted assets and liabilities in active markets that are accessible at the measurement date. •Level 2 Inputs —Quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. •Level 3 Inputs —Instruments with primarily unobservable market data that cannot be corroborated. The majority of our financial instruments are classified as Level 2 inputs. The availability of observable inputs can be affected by a wide variety of factors, including the type of instrument, whether the instrument is new and not yet established in the marketplace and other characteristics particular to the instrument. We typically obtain price estimates from multiple third- party pricing sources, such as pricing services and dealers, or, if applicable, the registered clearing exchange. We make inquiries of third-party pricing sources to understand the significant inputs and assumptions they used to determine their prices and that they are derived from orderly transactions, particularly during periods of elevated market turbulence and reduced market liquidity. We also review third-party price estimates and perform procedures to validate their reasonableness, including an analysis of the range of estimates for each position, comparison to recent trade activity for similar securities and for consistency with market conditions observed as of the measurement date. While we do not adjust prices we obtain from pricing sources, we will exclude prices for securities from our estimation of fair value if we determine based on our validation procedures and our market knowledge and expertise that the price is significantly different from what observable market data would indicate and we cannot obtain an understanding from the third-party source as to the significant inputs used to determine the price. The following is a description of the valuation methodologies used for instruments measured at fair value on a recurring basis classified as Level 2 inputs. These instruments trade in active markets such that participants transact with sufficient frequency and volume to provide transparent pricing information on an ongoing basis. The liquidity of these markets and the similarity of our securities and derivative instruments to those actively traded enable our pricing sources and us to observe quoted prices in the market and utilize those prices as a basis for formulating fair value measurements. Investment securities - are valued based on prices obtained from multiple third-party pricing sources. The pricing sources utilize various valuation approaches, including market and income approaches. For Agency RMBS, the pricing sources primarily utilize a matrix pricing technique that interpolates the estimated fair value based on observed quoted prices for forward contracts in the Agency RMBS "to-be-announced" market ("TBA securities") of the same coupon, maturity and issuer, adjusted to reflect the specific characteristics of the pool of mortgages underlying the Agency security, such as maximum loan balance, loan vintage, loan-to-value ratio, geography and other characteristics as may be appropriate. For other investment securities, the pricing sources primarily utilize discounted cash flow model-derived pricing techniques to estimate the fair value. Such models incorporate market-based discount rate assumptions based on observable inputs such as recent trading activity, credit data, volatility statistics, benchmark interest rate curves, spread measurements to benchmark curves and other market data that are current as of the measurement date and may include certain unobservable inputs, such as assumptions of future levels of prepayment, defaults and loss severities. TBA securities - are valued using prices obtained from third-party pricing sources based on pricing models that reference recent trading activity. Interest rate swaps - are valued using the daily settlement price, or fair value, determined by the clearing exchange based on a pricing model that references observable market inputs, including current benchmark rates and the forward yield curve. Interest rate swaptions - are valued using prices obtained from the counterparty and other third-party pricing models. The pricing models are based on the value of the future interest rate swap that we have the option to enter into as well as the remaining length of time that we have to exercise the option based on observable market inputs, adjusted for non-performance risk, if any. U.S. Treasury securities and futures are valued based on quoted prices for identical instruments in active markets and are classified as Level 1 assets. None of our financial instruments are classified as Level 3 inputs. Recent Accounting Pronouncements We consider the applicability and impact of all ASUs issued by the FASB. There are no unadopted ASUs that are expected to have a significant impact on our consolidated financial statements when adopted or other recently adopted ASUs that had a significant impact on our consolidated financial statements upon adoption.
Quarterly Financial Information [Text Block]	Basis of Presentation Our accompanying consolidated financial statements and related notes have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Article 10 of Regulation S-X. The accompanying consolidated financial statements and related notes are unaudited and include the accounts of all our wholly-owned subsidiaries and variable interest entities for which we are the primary beneficiary. Significant intercompany accounts and transactions have been eliminated. The accompanying consolidated financial statements and related notes should be read in conjunction with the audited consolidated financial statements included in our most recent Annual Report on Form 10-K for the fiscal year ended December 31, 2020. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of income and expenses during the reporting period. In the opinion of management, all adjustments, consisting solely of normal recurring accruals, necessary for the fair presentation of consolidated financial statements for the interim period have been included. The current period’s results of operations are not necessarily indicative of results that ultimately may be achieved for the year.

Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average Number of Shares Outstanding	524,900	559,100	528,700	553,300
Weighted Average Number of Fully Vested Restricted Stock Units and Performance Share Units Outstanding	1,700	1,200	1,400	900
Weighted Average Number of Shares Outstanding, Basic	526,600	560,300	530,100	554,200
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	0	500	1,800	0
Weighted Average Number of Shares Outstanding, Diluted	526,600	560,800	531,900	554,200
Net Income (Loss) Available to Common Stockholders, Basic	$ (436)	$ 693	$ 514	$ (1,749)
Earnings Per Share, Basic	$ (0.83)	$ 1.24	$ 0.97	$ (3.16)
Earnings Per Share, Diluted	$ (0.83)	$ 1.24	$ 0.97	$ (3.16)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,700			800

Net Income (Loss) Per Common Share (Notes)

6 Months Ended

Jun. 30, 2021

Net Income (Loss) Per Common Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Weighted average number of common shares issued and outstanding	524.9		559.1		528.7		553.3
Weighted average number of fully vested restricted stock units outstanding	1.7		1.2		1.4		0.9
Weighted average number of common shares outstanding - basic	526.6		560.3		530.1		554.2
Weighted average number of dilutive unvested restricted stock units outstanding	—		0.5		1.8		—
Weighted average number of common shares outstanding - diluted	526.6		560.8		531.9		554.2
Net income (loss) available (attributable) to common stockholders	$	(436)	$	693	$	514	$	(1,749)
Net income (loss) per common share - basic	$	(0.83)	$	1.24	$	0.97	$	(3.16)
Net income (loss) per common share - diluted	$	(0.83)	$	1.24	$	0.97	$	(3.16)

Earnings Per Share [Text Block]

Net Income (Loss) Per Common Share Basic net income (loss) per common share is computed by dividing (i) net income (loss) available (attributable) to common stockholders by (ii) the sum of our weighted-average number of common shares outstanding and the weighted-average number of vested but not yet issued time and performance-based restricted stock units ("RSUs") outstanding for the period granted under our long-term incentive program to employees and non-employee Board of Directors. Diluted net income (loss) per common share assumes the issuance of all potential common stock equivalents unless the effect is to reduce a loss or increase the income per common share. Our potential common stock equivalents consist of unvested time and performance-based RSUs. The following table presents the computations of basic and diluted net income (loss) per common share for the periods indicated (shares and dollars in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Weighted average number of common shares issued and outstanding	524.9		559.1		528.7		553.3
Weighted average number of fully vested restricted stock units outstanding	1.7		1.2		1.4		0.9
Weighted average number of common shares outstanding - basic	526.6		560.3		530.1		554.2
Weighted average number of dilutive unvested restricted stock units outstanding	—		0.5		1.8		—
Weighted average number of common shares outstanding - diluted	526.6		560.8		531.9		554.2
Net income (loss) available (attributable) to common stockholders	$	(436)	$	693	$	514	$	(1,749)
Net income (loss) per common share - basic	$	(0.83)	$	1.24	$	0.97	$	(3.16)
Net income (loss) per common share - diluted	$	(0.83)	$	1.24	$	0.97	$	(3.16)

For the three months ended June 30, 2021 and six months ended June 30, 2020, 1.7 million and 0.8 million, respectively, of potentially dilutive unvested time and performance based RSUs outstanding were excluded from the computation of diluted net income (loss) per common share because to do so would have been anti-dilutive for the period.

Pledged Assets (Securities Pledged as Collateral) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Offsetting Assets and Liabilities [Line Items]
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repo	$ 98	$ 119
Security Owned and Pledged as Collateral, Fair Value	50,319	54,314
Agency Securities Pledged As Collateral Amortized Cost	49,003	51,784
Agency Securities Pledged As Collateral Accrued Interest	128	147
Maturity Less than 30 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	31,779	29,674
Agency Securities Pledged As Collateral Amortized Cost	30,818	28,208
Agency Securities Pledged As Collateral Accrued Interest	84	82
Maturity 31 To 59 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	3,124	8,438
Agency Securities Pledged As Collateral Amortized Cost	3,002	8,013
Agency Securities Pledged As Collateral Accrued Interest	8	23
Maturity 60 To 90 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	5,788	5,782
Agency Securities Pledged As Collateral Amortized Cost	5,641	5,495
Agency Securities Pledged As Collateral Accrued Interest	15	16
Maturity over 90 days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	9,628	10,420
Agency Securities Pledged As Collateral Amortized Cost	9,542	10,068
Agency Securities Pledged As Collateral Accrued Interest	21	26
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	49,044	53,401
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	483	365
Credit Risk Transfer Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	502	455
Credit Risk Transfer Securities [Member] \| Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	502	455
Credit Risk Transfer Securities [Member] \| Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	0	0
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	1,005
Securities Received as Collateral, Amount Repledged and Sold	600
US Treasury Securities [Member] \| Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	733
US Treasury Securities [Member] \| Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	0
Non-Agency [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	377	458
Non-Agency [Member] \| Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	377	458
Non-Agency [Member] \| Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 0	$ 0

Repurchase Agreements and Reverse Repurchase Agreements (Tables)

6 Months Ended

Jun. 30, 2021

Disclosure of Repurchase Agreements [Abstract]

Schedule of Borrowings under Repurchase Agreements and Weighted Average Interest Rates

The following table summarizes our borrowings under repurchase agreements by their remaining maturities as of June 30, 2021 and December 31, 2020 (dollars in millions):


	June 30, 2021					December 31, 2020
Remaining Maturity	Repurchase Agreements		Weighted Average Interest Rate		Weighted Average Days to Maturity	Repurchase Agreements		Weighted Average Interest Rate		Weighted Average Days to Maturity
Agency repo:
≤ 1 month	$	31,093	0.10	%	11	$	29,505	0.22	%	12
> 1 to ≤ 3 months	8,794		0.15	%	67	13,434		0.27	%	57
> 3 to ≤ 6 months	1,662		0.12	%	148	7,317		0.28	%	142
> 6 to ≤ 9 months	5,916		0.15	%	199	660		0.24	%	208
> 9 to ≤ 12 months	875		0.18	%	303	1,450		0.15	%	354


Total Agency repo	48,340		0.11	%	54	52,366		0.24	%	54
U.S. Treasury repo:
> 1 day to ≤ 1 month	397		0.02	%	1	—		—	%	—
Total	$	48,737	0.11	%	54	$	52,366	0.24	%	54

Derivative and Other Hedging Instruments (Narrative) (Details) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($) month	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) month	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Interest Rate Swaption [Member]
Average Maturity (Years)		9 years 6 months		9 years 6 months
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration \| month		15		19
Notional Amount	$ 11,450			$ 11,450		$ 10,400
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(313)		$ (14)	74	$ (148)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	0		0	4,250	2,000
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	$ (1,700)		(200)	$ (3,200)	(1,500)
Derivative, Average Fixed Interest Rate	1.77%			1.77%		1.84%
Interest Rate Derivatives, at Fair Value, Net	$ 294			$ 294		$ 116
Options At Cost		$ 237		291
TBA and Forward Settling Agency Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	396		220	(530)	913
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	94,248		75,186	187,584	112,936
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period					(100,498)
US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(29)		(8)	32	(112)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(680)		(237)	763	(3,417)
Short [Member] \| US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(333)		(60)	474	(997)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	585		4,187	7,846	10,232
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	5,219		1,185	8,240	(12,209)
Long [Member] \| US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(1)		4	(11)	101
Trading Securities Added During the Period	1,336		550	2,651	7,011
Notional Amount Of Trading Securities Settlement Expiration During The Period	(939)		(2,987)	(2,254)	(5,974)
Debt Securities, Trading, and Equity Securities, FV-NI	$ 397	$ 0	$ 1,132	$ 397	$ 1,132	$ 0	$ 3,569	$ 95

Summary of Significant Accounting Policies (Details)	6 Months Ended
Summary of Significant Accounting Policies (Details)	Jun. 30, 2021
Derivative [Line Items]
Required Annual Distribution of Taxable Net Income	90.00%

Investment Securities Securities by Credit Rating (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	$ 48,749	$ 52,416
Debt Securities, Trading and Available-for-sale	59,799	66,414
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	200	188
Debt Securities, Trading and Available-for-sale	200	188
Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	353	358
Debt Securities, Trading and Available-for-sale	353	358
Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	1,105	737
Debt Securities, Trading and Available-for-sale	1,105	737
Securities Remeasured at Fair Value [Member] \| Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading and Available-for-sale	1,105	737
BBB Rating [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	77	83
BBB Rating [Member] \| Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	50	55
BBB Rating [Member] \| Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	72	28
BB Rating [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	42	36
BB Rating [Member] \| Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	89	43
BB Rating [Member] \| Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	222	167
AAA Rating [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
AAA Rating [Member] \| Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	21	35
AAA Rating [Member] \| Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
AA Rating [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	20	20
AA Rating [Member] \| Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	118	190
AA Rating [Member] \| Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
A Rating [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	36	32
A Rating [Member] \| Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	39	28
A Rating [Member] \| Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
B Rating [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	10	6
B Rating [Member] \| Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	36	7
B Rating [Member] \| Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	386	304
Not Rated [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	15	11
Not Rated [Member] \| Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
Not Rated [Member] \| Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	$ 425	$ 238

Investment Securities Investment Securities (Summary of Investment in Agency Security) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	$ 58,379	$ 63,701
Debt Securities, Trading and Available-for-sale	59,799	66,414
Total agency MBS, at fair value	58,141	65,131
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	187	178
Debt Securities, Trading and Available-for-sale	200	188
Commercial Mortgage Backed Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	336	333
Debt Securities, Trading and Available-for-sale	353	358
Credit Risk Transfer Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	1,081	733
Debt Securities, Trading and Available-for-sale	1,105	737
Fixed Income Securities [Member] \| Agency Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	56,418	61,977
Debt Securities, Trading and Available-for-sale	57,757	64,615
Adjustable-Rate [Member] \| Agency Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	54	69
Debt Securities, Trading and Available-for-sale	56	70
Collateralized Mortgage Obligations [Member] \| Agency Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	219	289
Debt Securities, Trading and Available-for-sale	228	301
Multifamily [Member] \| Agency Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	0	17
Debt Securities, Trading and Available-for-sale	0	19
Interest Only And Principal Only Strip [Member] \| Agency Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	84	105
Debt Securities, Trading and Available-for-sale	100	126
Agency Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	$ 56,775	$ 62,457

Derivative and Other Hedging Instruments (Tables)

6 Months Ended

Jun. 30, 2021

Derivative [Line Items]

Schedule of Interest Rate Swap Agreement by Receive Index (as a percentage of Notional Amount) [Table Text Block]


Pay Fixed / Receive Variable Interest Rate Swaps by Receive Index (% of Notional Amount)	June 30, 2021		December 31, 2020
SOFR	74	%	71	%
OIS	26	%	29	%
Total	100	%	100	%

Schedule of Outstanding Derivatives Not Designated as Hedging Instruments

The table below summarizes fair value information about our derivative and other hedging instrument assets/(liabilities) as of June 30, 2021 and December 31, 2020 (in millions):



Derivative and Other Hedging Instruments	Balance Sheet Location	June 30, 2021		December 31, 2020

Swaptions	Derivative assets, at fair value	$	294	$	116
TBA securities	Derivative assets, at fair value	87		275

Total derivative assets, at fair value		$	381	$	391


TBA securities	Derivative liabilities, at fair value	(8)		—
U.S. Treasury futures - short	Derivative liabilities, at fair value	(6)		(2)
Total derivative liabilities, at fair value		$	(14)	$	(2)

U.S. Treasury securities - long	U.S. Treasury securities, at fair value	$	397	$	—
U.S. Treasury securities - short	Obligation to return securities borrowed under reverse repurchase agreements, at fair value	(10,920)		(11,727)
Total U.S. Treasury securities, net at fair value		$	(10,523)	$	(11,727)

Schedule of Interest Rate Swaption Agreements Outstanding


Swaptions	Option					Underlying Payer Swap
Current Option Expiration Date	Cost Basis		Fair Value		Average Months to Current Option Expiration Date 1	Notional Amount		Average Fixed Pay Rate 2	Average Term (Years)
June 30, 2021
≤ 1 year	$	101	$	55	5	$	4,200	1.77%	8.8
> 1 year ≤ 2 years	80		117		20	3,250		1.41%	10.0
> 2 year ≤ 3 years	110		122		32	4,000		2.07%	10.0

Total	$	291	$	294	19	$	11,450	1.77%	9.5

December 31, 2020
≤ 1 year	$	123	$	15	5	$	5,900	2.17%	9.2
> 1 year ≤ 2 years	41		33		20	2,000		1.38%	10.0
> 2 year ≤ 3 years	65		60		33	2,250		1.40%	10.0
> 3 year ≤ 4 years	8		8		40	250		1.43%	10.0
Total	$	237	$	116	15	$	10,400	1.84%	9.5

________________________________

US government securities


U.S. Treasury Securities	June 30, 2021						December 31, 2020
Maturity	Face Amount Long/(Short)		Cost Basis 1		Fair Value		Face Amount Long/(Short)		Cost Basis 1		Fair Value
5 years	$	(1,665)	$	(1,648)	$	(1,631)	$	(425)	$	(425)	$	(425)
7 years	(1,083)		(1,072)		(1,049)		(1,083)		(1,081)		(1,089)
10 years	(7,748)		(7,740)		(7,843)		(9,780)		(9,862)		(10,213)
Total U.S. Treasury securities	$	(10,496)	$	(10,460)	$	(10,523)	$	(11,288)	$	(11,368)	$	(11,727)

________________________________

US Government Futures Securities [Table Text Block]


U.S. Treasury Futures	June 30, 2021								December 31, 2020
Maturity	Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1		Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1
10 years	$	(1,500)	$	(1,982)	$	(1,988)	$	(6)	$	(1,000)	$	(1,379)	$	(1,381)	$	(2)

________________________________

Summary of Long and Short Position of Derivative Instruments


	June 30, 2021								December 31, 2020
TBA Securities by Coupon	Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1		Notional Amount Long (Short)		Cost Basis		Fair Value		Net Carrying Value 1
15-Year TBA securities:
≤ 2.0%	$	418	$	422	$	423	1		$	6,540	$	6,708	$	6,771	$	63
2.5%	328		342		342		—		200		208		209		1



Total 15-Year TBA securities	746		764		765		1		6,740		6,916		6,980		64
30-Year TBA securities:
≤ 2.0%	2,551		2,552		2,572		20		19,805		20,314		20,480		166
2.5%	20,627		21,227		21,289		62		3,167		3,291		3,335		44
3.0%	2,104		2,195		2,193		(2)		528		552		553		1
3.5%	539		569		567		(2)		124		131		131		—


Total 30-Year TBA securities, net	25,821		26,543		26,621		78		23,624		24,288		24,499		211
Total TBA securities, net	$	26,567	$	27,307	$	27,386	$	79	$	30,364	$	31,204	$	31,479	$	275

________________________________

Schedule Of Outstanding Not Designated As Hedging Instruments


Derivative and Other Hedging Instruments	Beginning Notional Amount		Additions	Settlement, Termination, Expiration or Exercise	Ending Notional Amount		Gain/(Loss) on Derivative Instruments and Other Securities, Net 1
Three months ended June 30, 2021:
TBA securities, net	$	24,518	94,248	(92,199)	$	26,567	$	396
Forward settling non-Agency securities	$	—	300	—	$	300	—
Interest rate swaps - payer	$	49,725	—	—	$	49,725	(400)
Payer swaptions	$	13,150	—	(1,700)	$	11,450	(313)
U.S. Treasury securities - short position	$	(15,527)	(585)	5,219	$	(10,893)	(333)
U.S. Treasury securities - long position	$	—	1,336	(939)	$	397	(1)
U.S. Treasury futures contracts - short position	$	(1,000)	(2,000)	1,500	$	(1,500)	(29)
							$	(680)
Three months ended June 30, 2020:
TBA securities, net	$	20,279	75,186	(75,705)	$	19,760	$	220
Interest rate swaps - payer	$	46,475	25,750	(30,150)	$	42,075	(379)
Payer swaptions	$	9,550	—	(200)	$	9,350	(14)
U.S. Treasury securities - short position	$	(4,245)	(4,187)	1,185	$	(7,247)	(60)
U.S. Treasury securities - long position	$	3,569	550	(2,987)	$	1,132	4
U.S. Treasury futures contracts - short position	$	(1,000)	(1,000)	1,000	$	(1,000)	(8)
							$	(237)


Six months ended June 30, 2021:
TBA securities, net	$	30,364	187,584	(191,381)	$	26,567	$	(530)
Forward settling non-Agency securities	$	—	300	—	$	300	—
Interest rate swaps - payer	$	43,225	7,000	(500)	$	49,725	724
Payer swaptions	$	10,400	4,250	(3,200)	$	11,450	74
U.S. Treasury securities - short position	$	(11,287)	(7,846)	8,240	$	(10,893)	474
U.S. Treasury securities - long position	$	—	2,651	(2,254)	$	397	(11)
U.S. Treasury futures contracts - short position	$	(1,000)	(3,000)	2,500	$	(1,500)	32
							$	763
Six months ended June 30, 2020:
TBA securities, net	$	7,322	112,936	(100,498)	$	19,760	$	913
Interest rate swaps - payer	$	79,075	75,725	(112,725)	$	42,075	(3,174)
Payer swaptions	$	8,850	2,000	(1,500)	$	9,350	(148)
U.S. Treasury securities - short position	$	(9,224)	(10,232)	12,209	$	(7,247)	(997)
U.S. Treasury securities - long position	$	95	7,011	(5,974)	$	1,132	101
U.S. Treasury futures contracts - short position	$	(1,000)	(2,000)	2,000	$	(1,000)	(112)
							$	(3,417)

________________________________

1.Amounts exclude other miscellaneous gains and losses recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Amounts for the three and six months ended June 30, 2020 exclude $146 million of losses on debt extinguishment (see Note 4).

Not Designated as Hedging Instrument [Member]

Derivative [Line Items]

Schedule Of Interest Rate Swap Agreement By Remaining Maturity

The following tables summarize certain characteristics of our derivative and other hedging instruments outstanding as of June 30, 2021 and December 31, 2020 (dollars in millions):


	June 30, 2021					December 31, 2020
Pay Fixed / Receive Variable Interest Rate Swaps	Notional Amount		Average Fixed Pay Rate	Average Receive Rate	Average Maturity (Years)	Notional Amount		Average Fixed Pay Rate	Average Receive Rate	Average Maturity (Years)
≤ 3 years	$	16,000	0.11%	0.06%	2.3	$	8,750	0.04%	0.08%	2.4
> 3 to ≤ 5 years	18,500		0.13%	0.06%	3.9	17,000		0.10%	0.08%	4.1
> 5 to ≤ 7 years	7,050		0.21%	0.05%	5.5	9,800		0.21%	0.08%	5.8
> 7 to ≤ 10 years	6,700		0.36%	0.05%	8.1	6,200		0.28%	0.07%	8.5
> 10 years	1,475		0.47%	0.06%	13.7	1,475		0.47%	0.07%	14.2
Total	$	49,725	0.18%	0.06%	4.4	$	43,225	0.15%	0.08%	5.1

Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Dividends declared per common share	$ 0.36	$ 0.36	$ 0.72	$ 0.84
Net gain (loss) on sale of investment securities	$ 25	$ 153	$ 12	$ 647
Unrealized gain (loss) on investment securities measured at fair value through net income, net	(28)	679	(983)	876
(Loss) gain on derivative instruments and other securities, net	(618)	(385)	821	(3,539)
Nonoperating Income (Expense)	(621)	447	(150)	(2,016)
Interest income	249	429	806	920
Interest expense	17	134	46	560
Net interest income	232	295	760	360
Labor and Related Expense	12	13	28	26
General and administrative expenses	10	11	18	21
Total expenses	22	24	46	47
Net income (loss)	(411)	718	564	(1,703)
Dividend on preferred stock	25	25	50	46
Net income (loss) available (attributable) to common shareholders	(436)	693	514	(1,749)
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax	(77)	203	(314)	667
Comprehensive (loss) income	(488)	921	250	(1,036)
Comprehensive (loss) income (attributable) available to common shareholders	$ (513)	$ 896	$ 200	$ (1,082)
Weighted average number of common shares outstanding - basic	526.6	560.3	530.1	554.2
Weighted average number of common shares outstanding - diluted	526.6	560.8	531.9	554.2
Earnings Per Share, Basic	$ (0.83)	$ 1.24	$ 0.97	$ (3.16)
Net income (loss) per common share - diluted	$ (0.83)	$ 1.24	$ 0.97	$ (3.16)
Interest income:
Interest income	$ 249	$ 429	$ 806	$ 920
Interest expense	17	134	46	560
Net interest income	232	295	760	360
Other gain (loss), net:
Gain on sale of investment securities, net	25	153	12	647
Unrealized gain (loss) on investment securities measured at fair value through net income, net	(28)	679	(983)	876
Gain (loss) on derivative instruments and other securities, net	(618)	(385)	821	(3,539)
Expenses:
Compensation and benefits	12	13	28	26
Other operating expense	10	11	18	21
Total operating expense	22	24	46	47
Net income (loss)	(411)	718	564	(1,703)
Dividend on preferred stock	25	25	50	46
Net income (loss) available (attributable) to common stockholders	(436)	693	514	(1,749)
Other comprehensive income (loss):
Unrealized gain (loss) on investment securities measured at fair value through other comprehensive income (loss), net	77	(203)	314	(667)
Comprehensive income (loss)	(488)	921	250	(1,036)
Comprehensive income (loss) available (attributable) to common stockholders	$ (513)	$ 896	$ 200	$ (1,082)
Weighted average number of common shares outstanding - basic	526.6	560.3	530.1	554.2
Weighted average number of common shares outstanding - diluted	526.6	560.8	531.9	554.2
Net income (loss) per common share - basic	$ (0.83)	$ 1.24	$ 0.97	$ (3.16)
Net income (loss) per common share - diluted	$ (0.83)	$ 1.24	$ 0.97	$ (3.16)

Pledged Assets Repurchase Agreements with Counterparties Greater than or Equal to 5% of Equity at Risk (Details) $ in Millions	Jun. 30, 2021 USD ($) days	Dec. 31, 2020 USD ($) days
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Securities Sold under Agreements to Repurchase \| $	$ 48,737	$ 52,366
Risk Of Repurchase Agreement To Stockholders Equity	2.00%
Weighted Average Days to Maturity \| days	54	54
FICC [Member]
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Risk Of Repurchase Agreement To Stockholders Equity	8.00%

Derivative and Other Hedging Instruments (TBA Securities by Coupon and Issuer) (Details) - TBA and Forward Settling Agency Securities [Member] - USD ($) $ in Millions	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative, Notional Amount	$ 26,567	$ 24,518	$ 30,364	$ 19,760	$ 20,279	$ 7,322
Cost Basis	27,307		31,204
Net long TBA position, at fair value	27,386		31,479
TBA, net carrying value	79		275
30 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	25,821		23,624
Cost Basis	26,543		24,288
Net long TBA position, at fair value	26,621		24,499
TBA, net carrying value	78		211
30 Year Maturity [Member] \| 2.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	2,551		19,805
Cost Basis	2,552		20,314
Net long TBA position, at fair value	2,572		20,480
TBA, net carrying value	20		166
30 Year Maturity [Member] \| 2.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	20,627		3,167
Cost Basis	21,227		3,291
Net long TBA position, at fair value	21,289		3,335
TBA, net carrying value	62		44
30 Year Maturity [Member] \| 3.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	2,104		528
Cost Basis	2,195		552
Net long TBA position, at fair value	2,193		553
TBA, net carrying value	(2)		1
30 Year Maturity [Member] \| 3.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	539		124
Cost Basis	569		131
Net long TBA position, at fair value	567		131
TBA, net carrying value	(2)		0
15 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	746		6,740
Cost Basis	764		6,916
Net long TBA position, at fair value	765		6,980
TBA, net carrying value	1		64
15 Year Maturity [Member] \| 2.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	418		6,540
Cost Basis	422		6,708
Net long TBA position, at fair value	423		6,771
TBA, net carrying value	1		63
15 Year Maturity [Member] \| 2.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	328		200
Cost Basis	342		208
Net long TBA position, at fair value	342		209
TBA, net carrying value	$ 0		$ 1

Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Assets:
Agency securities, at fair value (including pledged securities of $49,686 and $53,698, respectively)	$ 57,896	$ 64,836
Agency securities transferred to consolidated variable interest entities, at fair value (pledged securities)	245	295
Credit risk transfer securities, at fair value (including pledged securities of $502 and $455, respectively)	1,105	737
Non-Agency securities, at fair value (including pledged securities of $377 and $458, respectively)	553	546
U.S. Treasury securities, at fair value (including pledged securities of $397 and $0, respectively)	397	0
Cash and cash equivalents	947	1,017
Restricted cash	623	1,307
Derivative assets, at fair value	381	391
Receivable for investment securities sold (including pledged securities of $147 and $207, respectively)	147	210
Receivable under reverse repurchase agreements	11,979	11,748
Goodwill and other intangible assets, net	526	526
Other assets	256	204
Total assets	75,055	81,817
Liabilities:
Repurchase Agreements	48,737	52,366
Debt of consolidated variable interest entities, at fair value	148	177
Payable for investment securities purchased	3,697	6,157
Derivative liabilities, at fair value	14	2
Dividends payable	88	90
Accounts payable and other liabilities	783	219
Total liabilities	64,387	70,738
Stockholders' equity:
Preferred Stock - aggregate liquidation preference of $1,538	1,489	1,489
Common stock - $0.01 par value; 1,500 shares authorized; 524.9 and 539.5 shares issued and outstanding, respectively	5	5
Additional paid-in capital	13,741	13,972
Retained deficit	(4,972)	(5,106)
Accumulated other comprehensive income	405	719
Total stockholders' equity	10,668	11,079
Total liabilities and stockholders' equity	75,055	81,817
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 10,920	$ 11,727

Derivative and Other Hedging Instruments (Remaining Interest Rate Swap Term) (Details) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($) month	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) month	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (680)		$ (237)	$ 763	$ (3,417)
Interest Rate Swaps Linked to Overnight Index Swap Rate	26.00%			26.00%		29.00%
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (313)		(14)	$ 74	(148)
Cost		$ 237		291
Fair Value	294			$ 294		$ 116
Average Months to Expiration \| month		15		19
Derivative Liability, Notional Amount	$ 11,450			$ 11,450		$ 10,400
Average Fixed Pay Rate	1.77%			1.77%		1.84%
Average Maturity (Years)		9 years 6 months		9 years 6 months
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (400)		$ (379)	$ 724	$ (3,174)
Derivative Liability, Notional Amount	$ 49,725			$ 49,725		$ 43,225
Average Fixed Pay Rate	0.18%			0.18%		0.15%
Average Maturity (Years)		5 years 1 month 6 days		4 years 4 months 24 days
Less Than or Equal to One Year [Member] \| Interest Rate Swaption [Member]
Cost		$ 123		$ 101
Fair Value	$ 55			$ 55		$ 15
Average Months to Expiration \| month		5		5
Derivative Liability, Notional Amount	$ 4,200			$ 4,200		$ 5,900
Average Fixed Pay Rate	1.77%			1.77%		2.17%
Average Maturity (Years)		9 years 2 months 12 days		8 years 9 months 18 days
Greater Than One Year and Less Than or Equal to Three Years [Member] \| Interest Rate Swap [Member]
Derivative Liability, Notional Amount	$ 16,000			$ 16,000		$ 8,750
Average Fixed Pay Rate	0.11%			0.11%		0.04%
Average Maturity (Years)		2 years 4 months 24 days		2 years 3 months 18 days
Bermudan [Member] \| Interest Rate Swaption [Member]
Derivative Liability, Notional Amount	$ 700			$ 700

Consolidated Statement of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance, value at Dec. 31, 2019	$ 11,041,000	$ 932,000	$ 5,000	$ 13,893,000	$ (3,886,000)	$ 97,000
Balance, Common Stock, shares at Dec. 31, 2019			540,900
Net income (loss)	(1,703,000)				(1,703,000)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	$ 667,000					667,000
Shares Issued, Shares, Share-based Payment Arrangement, before Forfeiture	100
APIC, Share-based Payment Arrangement, Recognition and Exercise	$ 7,000			7,000
Stock Repurchased During Period, Shares			(12,200)
Proceeds from Issuance of Preferred Stock and Preference Stock	557,000
Stock Issued During Period, Shares, New Issues			26,700
Stock Issued During Period, Value, New Issues	439,000		$ 1,000	438,000
Stock Repurchased During Period, Value	147,000			147,000
Payments for Repurchase of Common Stock	147,000
Preferred dividends declared	(46,000)				(46,000)
Common dividends declared	(465,000)				(465,000)
Balance, value at Jun. 30, 2020	10,350,000	1,489,000	$ 6,000	14,191,000	(6,100,000)	764,000
Balance, Common Stock, shares at Jun. 30, 2020			555,500
Balance, value at Mar. 31, 2020	9,798,000	1,489,000	$ 6,000	14,334,000	(6,592,000)	561,000
Balance, Common Stock, shares at Mar. 31, 2020			567,700
Net income (loss)	718,000				718,000
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	$ 203,000					203,000
Shares Issued, Shares, Share-based Payment Arrangement, before Forfeiture	0
APIC, Share-based Payment Arrangement, Recognition and Exercise	$ 4,000			4,000
Stock Repurchased During Period, Shares			(12,200)
Stock Repurchased During Period, Value	147,000			147,000
Preferred dividends declared	(25,000)				(25,000)
Common dividends declared	(201,000)				(201,000)
Balance, value at Jun. 30, 2020	10,350,000	1,489,000	$ 6,000	14,191,000	(6,100,000)	764,000
Balance, Common Stock, shares at Jun. 30, 2020			555,500
Balance, value at Dec. 31, 2020	$ 11,079,000	1,489,000	$ 5,000	13,972,000	(5,106,000)	719,000
Balance, Common Stock, shares at Dec. 31, 2020	539,500		539,500
Net income (loss)	$ 564,000				564,000
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	$ (314,000)					(314,000)
Shares Issued, Shares, Share-based Payment Arrangement, before Forfeiture	400
APIC, Share-based Payment Arrangement, Recognition and Exercise	$ 8,000			8,000
Stock Repurchased During Period, Shares	(15,000)
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 0
Stock Repurchased During Period, Value	239,000		$ 0	239,000
Payments for Repurchase of Common Stock	239,000
Preferred dividends declared	(50,000)				(50,000)
Common dividends declared	(380,000)				(380,000)
Balance, value at Jun. 30, 2021	$ 10,668,000	1,489,000	$ 5,000	13,741,000	(4,972,000)	405,000
Balance, Common Stock, shares at Jun. 30, 2021	524,900		524,900
Balance, value at Mar. 31, 2021	$ 11,364,000	1,489,000	$ 5,000	13,736,000	(4,348,000)	482,000
Balance, Common Stock, shares at Mar. 31, 2021			524,900
Net income (loss)	(411,000)				(411,000)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(77,000)					(77,000)
APIC, Share-based Payment Arrangement, Recognition and Exercise	5,000			5,000
Preferred dividends declared	(25,000)				(25,000)
Common dividends declared	(188,000)				(188,000)
Balance, value at Jun. 30, 2021	$ 10,668,000	$ 1,489,000	$ 5,000	$ 13,741,000	$ (4,972,000)	$ 405,000
Balance, Common Stock, shares at Jun. 30, 2021	524,900		524,900

Stockholders' Equity Schedule of Dividends Declared (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends declared per common share	$ 0.36	$ 0.36	$ 0.72	$ 0.84

Pledged Assets (Assets Pledged from Counterparties) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Offsetting Assets and Liabilities [Line Items]
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 10,920	$ 11,727
Restricted Cash and Cash Equivalents	623	1,307
Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	315	110
Restricted Cash and Securities Pledged	13,351	11,850
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] \| Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	(13)	(13)
Restricted Cash and Cash Equivalents	1	3
Securities Sold under Agreements to Repurchase [Member] \| Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	(14)	(16)
Derivative [Member] \| Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Securities Pledged	314	107
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Securities Received as Collateral, Amount Repledged and Sold	600
US Treasury Securities [Member] \| Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	(13,036)	(11,740)
Reverse Repurchase Agreements [Member] \| Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	(13,023)	(11,727)
Reverse Repurchase Agreements [Member] \| US Treasury Securities [Member] \| Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	(13,023)	(11,727)
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	604	890
Derivative [Member] \| US Treasury Securities [Member] \| Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	0	0
Derivative [Member] \| Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	$ 314	$ 107

Label	Element	Value
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 2,324,000,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 1,282,000,000

Stockholders' Equity

6 Months Ended

Jun. 30, 2021

Equity [Abstract]

Stockholders' Equity

Preferred Stock

We are authorized to designate and issue up to 10.0 million shares of preferred stock in one or more classes or series. As of June 30, 2021 and December 31, 2020, 13,800, 10,350, 16,100 and 23,000 shares of preferred stock were designated as 7.00% Series C Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock, 6.875% Series D Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock, 6.50% Series E Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock and 6.125% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock, respectively, (referred to as "Series C, D, E and F Preferred Stock", respectively). As of June 30, 2021 and December 31, 2020, 13,000, 9,400, 16,100 and 23,000 shares of Series C, D, E and F Preferred Stock, respectively, were issued and outstanding. Each share of preferred stock is represented by 1,000 depositary shares. Each share of preferred stock has a liquidation preference of $25,000 per share (or $25 per depositary share).

Our preferred stock ranks senior to our common stock with respect to the payment of dividends and the distribution of assets upon a voluntary or involuntary liquidation, dissolution or winding up of the Company. Our preferred stock has no stated maturity, is not subject to any sinking fund or mandatory redemption and each series of preferred stock ranks on parity with one another. Under certain circumstances upon a change of control, our preferred stock is convertible to shares of our common stock. Holders of our preferred stock and depositary shares underlying our preferred stock have no voting rights, except under limited conditions. Beginning on each series' optional redemption date, we may redeem shares at $25.00 per depositary share, plus accumulated and unpaid dividends (whether or not declared), exclusively at our option.

The following table includes a summary of preferred stock depositary shares issued and outstanding as of June 30, 2021 (dollars and shares in millions):


Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock 1	Issuance Date	Depositary Shares Issued and Outstanding	Carrying Value		Aggregate Liquidation Preference		Fixed Rate	Optional Redemption Date 2	Fixed-to-Floating Rate Conversion Date	Floating Annual Rate
Series C	August 22, 2017	13.0	315		325		7.000%	October 15, 2022	October 15, 2022	3M LIBOR + 5.111%
Series D	March 6, 2019	9.4	227		235		6.875%	April 15, 2024	April 15, 2024	3M LIBOR + 4.332%
Series E	October 3, 2019	16.1	390		403		6.500%	October 15, 2024	October 15, 2024	3M LIBOR + 4.993%
Series F	February 11, 2020	23.0	557		575		6.125%	April 15, 2025	April 15, 2025	3M LIBOR + 4.697%
Total		61.5	$	1,489	$	1,538

________________________________

1.Fixed-to-floating rate redeemable preferred stock accrue dividends at an annual fixed rate of the $25.00 liquidation preference per depositary share from the issuance date up to, but not including, the fixed-to-floating rate conversion date; thereafter, dividends will accrue on a floating rate basis equal to 3-month LIBOR plus a fixed spread.

2.Shares may be redeemed prior to our optional redemption date under certain circumstances intended to preserve our qualification as a REIT for U.S federal income tax purposes.

At-the-Market Offering Program

We are authorized by our Board of Directors to enter into agreements with sales agents to publicly offer and sell shares of our common stock in privately negotiated and/or at-the-market transactions from time-to-time up to a maximum aggregate offering price of our common stock. As of June 30, 2021, shares of our common stock with an aggregate offering price of $1.25 billion remained authorized for issuance under this program through June 11, 2024. We did not issue shares under the program during the six months ended June 30, 2021.

Common Stock Repurchase Program

We are authorized by our Board of Directors to repurchase shares of our common stock in open market or through privately negotiated transactions or pursuant to a trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"). During the three months ended March 31, 2021, we repurchased 15.0 million shares, or $239 million, of our common stock for an average repurchase price of $16.00 per common share, inclusive of transaction costs and including amounts repurchased in December 2020 that settled in January 2021. During the three months ended June 30, 2021, we did not repurchase shares of our common stock. As of June 30, 2021, shares of our common stock with an aggregate repurchase price of $684 million remained authorized for repurchase through December 31, 2021.

Accumulated Other Comprehensive Income (Loss)

The following table summarizes changes to accumulated OCI for the three and six months ended June 30, 2021 and 2020 (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
Accumulated Other Comprehensive Income (Loss)	2021		2020		2021		2020
Beginning Balance	$	482	$	561	$	719	$	97
OCI before reclassifications	(63)		242		(282)		707
Net loss amounts for available-for-sale securities reclassified from accumulated OCI to realized gain (loss) on sale of investment securities, net	(14)		(39)		(32)		(40)
Ending Balance	$	405	$	764	$	405	$	764

Derivative and Other Hedging Instruments (Effect Of Derivative Instruments Not Designated As Hedges On Comprehensive Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	$ (680,000)	$ (237,000)	$ 763,000	$ (3,417,000)
Gain (Loss) on Extinguishment of Debt				(146,000)
Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(11,450,000)	(9,350,000)	(11,450,000)	(9,350,000)	$ (13,150,000)	$ (10,400,000)	$ (9,550,000)
Additions	0	0	(4,250,000)	(2,000,000)
Settlement, Expirations or Exercise	1,700,000	200,000	3,200,000	1,500,000
Notional Amount	(11,450,000)		(11,450,000)
Amount Gain/(Loss) Recognized in Income on Derivatives	(313,000)	(14,000)	74,000	(148,000)
TBA and Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(26,567,000)	(19,760,000)	(26,567,000)	(19,760,000)	(24,518,000)	(30,364,000)	(20,279,000)	$ (7,322,000)
Additions	(94,248,000)	(75,186,000)	(187,584,000)	(112,936,000)
Settlement, Expirations or Exercise				100,498,000
Amount Gain/(Loss) Recognized in Income on Derivatives	396,000	220,000	(530,000)	913,000
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Settlement, Expirations or Exercise	92,199,000	75,705,000	191,381,000
Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Additions	0	(25,750,000)	(7,000,000)	(75,725,000)
Settlement, Expirations or Exercise	0	30,150,000	500,000	112,725,000
Notional Amount	(49,725,000)		(49,725,000)
Amount Gain/(Loss) Recognized in Income on Derivatives	(400,000)	(379,000)	724,000	(3,174,000)
US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	(29,000)	(8,000)	32,000	(112,000)
Forward Settling non-Agency Securities
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(300,000)		(300,000)		0	0
Additions	(300,000)		(300,000)
Amount Gain/(Loss) Recognized in Income on Derivatives	0		0
Purchases Of Forward Settling non-Agency Securities
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Settlement, Expirations or Exercise	0		0
Not Designated as Hedging Instrument [Member] \| Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount								(8,850,000)
Not Designated as Hedging Instrument [Member] \| Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(49,725,000)	(42,075,000)	(49,725,000)	(42,075,000)	(49,725,000)	(43,225,000)	(46,475,000)	(79,075,000)
Short [Member] \| US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(10,893,000)	(7,247,000)	(10,893,000)	(7,247,000)	(15,527,000)	(11,287,000)	(4,245,000)	(9,224,000)
Additions	(585,000)	(4,187,000)	(7,846,000)	(10,232,000)
Settlement, Expirations or Exercise	(5,219,000)	(1,185,000)	(8,240,000)	12,209,000
Amount Gain/(Loss) Recognized in Income on Derivatives	(333,000)	(60,000)	474,000	(997,000)
Long [Member] \| US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	(1,000)	4,000	(11,000)	101,000
Debt Securities, Trading, and Equity Securities, FV-NI	397,000	1,132,000	397,000	1,132,000	0	0	3,569,000	95,000
Trading Securities Added During the Period	1,336,000	550,000	2,651,000	7,011,000
Notional Amount Of Trading Securities Settlement Expiration During The Period	(939,000)	(2,987,000)	(2,254,000)	(5,974,000)
Future [Member] \| Short [Member] \| US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(1,500,000)	(1,000,000)	(1,500,000)	(1,000,000)	$ (1,000,000)	$ (1,000,000)	$ (1,000,000)	$ (1,000,000)
Additions	2,000,000	1,000,000	3,000,000	(2,000,000)
Settlement, Expirations or Exercise	$ (1,500,000)	$ (1,000,000)	$ (2,500,000)	$ 2,000,000

Repurchase Agreements And Other Debt (Repurchase Arrangements And Weighted Average Interest Rates Classified By Original Maturities) (Details) $ in Millions	Jun. 30, 2021 USD ($) days	Dec. 31, 2020 USD ($) days
Receivable Under Reverse Repurchase Agreements	$ 11,979	$ 11,748
Repurchase Agreements	$ 48,737	$ 52,366
Weighted Average Interest Rate	0.11%	0.24%
Weighted Average Days to Maturity \| days	54	54
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 10,920	$ 11,727
Maturity Overnight [Member]
Repurchase Agreements	7,400	11,200
30 Days or Less [Member]
Repurchase Agreements	$ 31,093	$ 29,505
Weighted Average Interest Rate	0.10%	0.22%
Weighted Average Days to Maturity \| days	11	12
1 to 3 Months
Repurchase Agreements	$ 8,794	$ 13,434
Weighted Average Interest Rate	0.15%	0.27%
Weighted Average Days to Maturity \| days	67	57
3 to 6 Months
Repurchase Agreements	$ 1,662	$ 7,317
Weighted Average Interest Rate	0.12%	0.28%
Weighted Average Days to Maturity \| days	148	142
6 to 9 Months
Repurchase Agreements	$ 5,916	$ 660
Weighted Average Interest Rate	0.15%	0.24%
Weighted Average Days to Maturity \| days	199	208
9 to 12 Months
Repurchase Agreements	$ 875	$ 1,450
Weighted Average Interest Rate	0.18%	0.15%
Weighted Average Days to Maturity \| days	303	354
US Treasury Securities [Member] \| 2 Days to 1 Month [Member]
Repurchase Agreements	$ 397	$ 0
Weighted Average Interest Rate	0.02%	0.00%
Weighted Average Days to Maturity \| days	1	0
FICC [Member]
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 2,700	$ 3,600
US Government Agencies Debt Securities [Member]
Repurchase Agreements	$ 48,340	$ 52,366
Weighted Average Interest Rate	0.11%	0.24%
Weighted Average Days to Maturity \| days	54	54

Pledged Assets

6 Months Ended

Jun. 30, 2021

Pledged Assets [Abstract]

Pledged Assets

Our funding agreements require us to fully collateralize our obligations under the agreements based upon our counterparties' collateral requirements and their determination of the fair value of the securities pledged as collateral, which fluctuates with changes in interest rates, credit quality and liquidity conditions within the investment banking, mortgage finance and real estate industries. Our derivative contracts similarly require us to fully collateralize our obligations under such agreements, which will vary over time based on similar factors as well as our counterparties' determination of the value of the derivative contract. We are typically required to post initial margin upon execution of derivative transactions, such as under our interest rate swap agreements and TBA contracts, and subsequently post or receive variation margin based on daily fluctuations in fair value. Our brokerage and custody agreements and the clearing organizations utilized by our wholly-owned captive broker-dealer subsidiary, Bethesda Securities, LLC, also require that we post minimum daily clearing deposits. If we breach our collateral requirements, we will be required to fully settle our obligations under the agreements, which could include a forced liquidation of our pledged collateral.

Our counterparties also apply a "haircut" to our pledged collateral, which means our collateral is valued at slightly less than market value and limits the amount we can borrow against our securities. This haircut reflects the underlying risk of the specific collateral and protects our counterparty against a change in its value. Our agreements do not specify the haircut; rather, haircuts are determined on an individual transaction basis. Consequently, our funding agreements and derivative contracts expose us to credit risk relating to potential losses that could be recognized if our counterparties fail to perform their obligations under such agreements. We minimize this risk by limiting our counterparties to major financial institutions with acceptable credit ratings or to registered clearinghouses and U.S. government agencies, and we monitor our positions with individual counterparties. In the event of a default by a counterparty, we may have difficulty obtaining our assets pledged as collateral to such counterparty and may not receive payments as and when due to us under the terms of our derivative agreements. In the case of centrally cleared instruments, we could be exposed to credit risk if the central clearing agency or a clearing member defaults on its respective obligation to perform under the contract. However, we believe that the risk is minimal due to the clearing exchanges' initial and daily mark-to-market margin requirements, clearinghouse guarantee funds and other resources that are available in the event of a clearing member default.

As of June 30, 2021, our maximum amount at risk with any counterparty related to our repurchase agreements, excluding the Fixed Income Clearing Corporation, was less than 2% of our tangible stockholders' equity (or the excess/shortfall of the value of collateral pledged/received over our repurchase agreement liabilities/reverse repurchase agreement receivables). As of June 30, 2021, approximately 8% of our tangible stockholder's equity was at risk with the Fixed Income Clearing Corporation.

Assets Pledged to Counterparties


	June 30, 2021
Assets Pledged to Counterparties 1	Repurchase Agreements 2		Debt of Consolidated VIEs		Derivative Agreements		Brokerage and Clearing Agreements 3		Total
Agency RMBS - fair value	$	49,044	$	245	$	483	$	404	$	50,176
CRT - fair value	502		—		—		—		502
Non-Agency - fair value	377		—		—		—		377
U.S. Treasury securities - fair value	733		—		—		272		1,005
Accrued interest on pledged securities	128		1		1		1		131
Restricted cash	19		—		604		—		623
Total	$	50,803	$	246	$	1,088	$	677	$	52,814


	December 31, 2020
Assets Pledged to Counterparties 1	Repurchase Agreements 2		Debt of Consolidated VIEs		Derivative Agreements		Brokerage and Clearing Agreements 3		Total
Agency RMBS - fair value	$	53,401	$	295	$	365	$	258	$	54,319
CRT - fair value	455		—		—		—		455
Non-Agency - fair value	458		—		—		—		458

Accrued interest on pledged securities	147		1		1		1		150
Restricted cash	417		—		890		—		1,307
Total	$	54,878	$	296	$	1,256	$	259	$	56,689

________________________________

1.Includes repledged assets received as collateral from counterparties and securities sold but not yet settled.

2.Includes $98 million and $119 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of June 30, 2021 and December 31, 2020, respectively.

3.Includes margin for TBAs cleared through prime brokers and other clearing deposits.


	June 30, 2021						December 31, 2020
Securities Pledged by Remaining Maturity of Repurchase Agreements 1,2	Fair Value of Pledged Securities		Amortized Cost of Pledged Securities		Accrued Interest on Pledged Securities		Fair Value of Pledged Securities		Amortized Cost of Pledged Securities		Accrued Interest on Pledged Securities
≤ 30 days	$	31,779	$	30,818	$	84	$	29,674	$	28,208	$	82
> 30 and ≤ 60 days	3,124		3,002		8		8,438		8,013		23
> 60 and ≤ 90 days	5,788		5,641		15		5,782		5,495		16
> 90 days	9,628		9,542		21		10,420		10,068		26
Total	$	50,319	$	49,003	$	128	$	54,314	$	51,784	$	147

________________________________

1.Includes $98 million and $119 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of June 30, 2021 and December 31, 2020, respectively.

2.Excludes $0.6 billion of repledged U.S. Treasury securities received as collateral from counterparties as of June 30, 2021.

Assets Pledged from Counterparties


	June 30, 2021								December 31, 2020
Assets Pledged to AGNC	Reverse Repurchase Agreements		Derivative Agreements		Repurchase Agreements		Total		Reverse Repurchase Agreements		Derivative Agreements		Repurchase Agreements		Total
U.S. Treasury securities - fair value 1	$	13,023	$	—	$	13	$	13,036	$	11,727	$	—	$	13	$	11,740
Cash	—		314		1		315		—		107		3		110
Total	$	13,023	$	314	$	14	$	13,351	$	11,727	$	107	$	16	$	11,850

________________________________

Offsetting Assets and Liabilities

Certain of our repurchase agreements and derivative transactions are governed by underlying agreements that generally provide for a right of setoff under master netting arrangements (or similar agreements), including in the event of default or in the event of bankruptcy of either party to the transactions. We present our assets and liabilities subject to such arrangements on a gross basis in our consolidated balance sheets. The following tables present information about our assets and liabilities that are subject to master netting arrangements and can potentially be offset on our consolidated balance sheets as of June 30, 2021 and December 31, 2020 (in millions):


	Offsetting of Financial and Derivative Assets
	Gross Amounts of Recognized Assets		Gross Amounts Offset in the Consolidated Balance Sheets		Net Amounts of Assets Presented in the Consolidated Balance Sheets		Gross Amounts Not Offset in the Consolidated Balance Sheets				Net Amount
							Financial Instruments		Collateral Received 2
June 30, 2021
Interest rate swap and swaption agreements, at fair value 1	$	294	$	—	$	294	$	—	$	(293)	$	1
TBA securities, at fair value	87		—		87		(8)		—		79
Receivable under reverse repurchase agreements	11,979		—		11,979		(7,216)		(4,763)		—
Total	$	12,360	$	—	$	12,360	$	(7,224)	$	(5,056)	$	80

December 31, 2020
Interest rate swap and swaption agreements, at fair value 1	$	116	$	—	$	116	$	—	$	(105)	$	11
TBA securities, at fair value	275		—		275		—		—		275
Receivable under reverse repurchase agreements	11,748		—		11,748		(6,522)		(5,223)		3
Total	$	12,139	$	—	$	12,139	$	(6,522)	$	(5,328)	$	289


	Offsetting of Financial and Derivative Liabilities
	Gross Amounts of Recognized Liabilities		Gross Amounts Offset in the Consolidated Balance Sheets		Net Amounts of Liabilities Presented in the Consolidated Balance Sheets		Gross Amounts Not Offset in the Consolidated Balance Sheets				Net Amount
							Financial Instruments		Collateral Pledged 2
June 30, 2021

TBA securities, at fair value	$	8	$	—	$	8	$	(8)	$	—	$	—
Repurchase agreements	48,737		—		48,737		(7,216)		(41,520)		1
Total	$	48,745	$	—	$	48,745	$	(7,224)	$	(41,520)	$	1

December 31, 2020


Repurchase agreements	$	52,366	$	—	$	52,366	$	(6,522)	$	(45,844)	$	—
Total	$	52,366	$	—	$	52,366	$	(6,522)	$	(45,844)	$	—

________________________________