AGNC Investment (AGNC) 10-K 25 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Jan. 31, 2020	Jun. 30, 2019
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-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Entity File Number	001-34057
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
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		540,943,011
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Public Float			$ 7.4
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

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Assets:
Agency securities, at fair value (including pledged securities of $92,608 and $78,619, respectively)	$ 98,516	$ 82,291
Agency securities transferred to consolidated variable interest entities, at fair value (pledged securities)	371	436
Credit risk transfer securities, at fair value (including pledged securities of $309 and $141, respectively)	976	1,012
Non-Agency securities, at fair value (including pledged securities of $0 and $45, respectively)	579	548
U.S. Treasury securities, at fair value (including pledged securities of $97 and $0, respectively)	97	46
Cash and cash equivalents	831	921
Restricted cash and cash equivalents	451	599
Derivative assets, at fair value	190	273
Receivable for investment securities sold (pledged securities)	0	489
Receivable under reverse repurchase agreements	10,181	21,813
Goodwill and other intangible assets, net	526	526
Other assets	364	287
Total assets	113,082	109,241
Liabilities:
Repurchase Agreements	89,182	75,717
Debt of consolidated variable interest entities, at fair value	228	275
Payable for investment securities purchased	2,554	1,204
Derivative liabilities, at fair value	6	84
Dividends payable	104	106
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	9,543	21,431
Accounts payable and other liabilities	424	518
Total liabilities	102,041	99,335
Stockholders' equity:
Preferred Stock - aggregate liquidation preference of $963 and $500, respectively	932	484
Common stock - $0.01 par value; 900 shares authorized; 540.9 and 536.3 shares issued and outstanding, respectively	5	5
Additional paid-in capital	13,893	13,793
Retained deficit	(3,886)	(3,433)
Accumulated other comprehensive income (loss)	97	(943)
Total stockholders' equity	11,041	9,906
Total liabilities and stockholders' equity	$ 113,082	$ 109,241

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 92,547	$ 79,182
Preferred Stock, Liquidation Preference, Value	963	$ 500
Preferred Stock C, Liquidation Preference, Value	325
Preferred Stock D, Liquidation Preference, Value	$ 235
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	900	900
Common Stock, Shares, Issued	540.9	536.3
Common Stock, Shares, Outstanding	540.9	536.3
Agency Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 92,608	$ 78,619
Credit Risk Transfer Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	309	141
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	0	45
US Treasury Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	481	437
Receivable for securities sold [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	0	489
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	$ 97	$ 0

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Issuance costs of redeemed preferred stock	$ 6	$ 0	$ 0	$ 0					$ 6	$ 0	$ 6
Dividends declared per common share	$ 0.48	$ 0.48	$ 0.50	$ 0.54	$ 0.54	$ 0.54	$ 0.54	$ 0.54
Interest income:
Interest income	$ 768	$ 676	$ 693	$ 705	$ 604	$ 500	$ 414	$ 431	2,842	1,949	1,293
Interest expense	481	557	570	541	418	312	237	206	2,149	1,173	524
Net interest income	287	119	123	164	186	188	177	225	693	776	769
Other gain (loss), net:
Gain (loss) on sale of investment securities, net	107	89	132	60	(21)	(40)	(74)	(2)	388	(137)	(63)
Unrealized gain (loss) on investment securities measured at fair value through net income, net	(160)	355	759	1,060	683	(363)	(94)	(523)	2,014	(297)	(71)
Gain (loss) on derivative instruments and other securities, net	662	(548)	(1,438)	(1,000)	(1,633)	430	298	738	(2,324)	(167)	193
Management Fee Income					0	46	4	4	0	54	16
Total other gain (loss), net:	609	(104)	(547)	120	(971)	73	134	217	78	(547)	75
Expenses:
Compensation and benefits	16	10	11	10	11	14	10	10	47	45	42
Other operating expense	9	9	9	9	8	31	8	8	36	55	31
Total operating expense	25	19	20	19	19	45	18	18	83	100	73
Net income	871	(4)	(444)	265	(804)	216	293	424	688	129	771
Dividend on preferred stock	18	13	13	10	9	9	9	9	54	36	32
Net income available to common stockholders	847	(17)	(457)	255	(813)	207	284	415	628	93	733
Other comprehensive income (loss):
Unrealized gain (loss) on investment securities measured at fair value through other comprehensive income (loss), net	(15)	(246)	(379)	(400)	(361)	193	145	621	(1,040)	598	(52)
Comprehensive income (loss)	886	242	(65)	665	(443)	23	148	(197)	1,728	(469)	823
Comprehensive income (loss) available (attributable) to common stockholders	$ 862	$ 229	$ (78)	$ 655	$ (452)	$ 14	$ 139	$ (206)	$ 1,668	$ (505)	$ 785
Weighted average number of common shares outstanding - basic	541.4	546.4	537.8	536.7		462.3	404.9	391.3	540.6	441.1	358.6
Weighted average number of common shares outstanding - diluted	542.6	546.4	537.8	537.2	504.2	462.7	405.2	391.5	541.4	441.4	358.7
Net income per common share - basic	$ 1.56	$ (0.03)	$ (0.85)	$ 0.48	$ (1.61)	$ 0.45	$ 0.70	$ 1.06	$ 1.16	$ 0.21	$ 2.04
Net income per common share - diluted	$ 1.56	$ (0.03)	$ (0.85)	$ 0.47					$ 1.16	$ 0.21	$ 2.04

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	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, 2016	$ 7,356	$ 336	$ 3	$ 9,932	$ (2,518)	$ (397)
Balance, Common Stock, shares at Dec. 31, 2016			331
Net income (loss)	771				771
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	52					52
APIC, Share-based Payment Arrangement, Recognition and Exercise	4			4
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 315
Stock Redeemed or Called During Period, Shares	(167)
Preferred Stock, Redemption Amount	$ (173)
Issuance costs of redeemed preferred stock	$ (6)
Stock Issued During Period, Shares, New Issues	7.6		60.3
Stock Issued During Period, Value, New Issues	$ 1,238		$ 1	1,237
Payments for Repurchase of Common Stock	0
Preferred dividends declared	(32)				(32)
Common dividends declared	(777)				(777)
Balance, value at Dec. 31, 2017	8,754	484	$ 4	11,173	(2,562)	(345)
Balance, Common Stock, shares at Dec. 31, 2017			391.3
Net income (loss)	129				129
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(598)					(598)
APIC, Share-based Payment Arrangement, Recognition and Exercise	10			10
Proceeds from Issuance of Preferred Stock and Preference Stock	0
Issuance costs of redeemed preferred stock	$ 0
Stock Issued During Period, Shares, New Issues	20.8		145
Stock Issued During Period, Value, New Issues	$ 2,611		$ 1	2,610
Payments for Repurchase of Common Stock	0
Preferred dividends declared	(36)				(36)
Common dividends declared	(964)				(964)
Balance, value at Dec. 31, 2018	$ 9,906	484	$ 5	13,793	(3,433)	(943)
Balance, Common Stock, shares at Dec. 31, 2018	536.3		536.3
Net income (loss)	$ 688				688
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	$ 1,040					1,040
Shares Issued, Shares, Share-based Payment Arrangement, before Forfeiture	0.1
APIC, Share-based Payment Arrangement, Recognition and Exercise	$ 13			13
Stock Repurchased During Period, Shares	(6.9)		(6.9)
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 617
Stock Redeemed or Called During Period, Shares	(169)
Preferred Stock, Redemption Amount	$ (175)
Issuance costs of redeemed preferred stock	$ (6)
Stock Issued During Period, Shares, New Issues	11.4		11.4
Stock Issued During Period, Value, New Issues	$ 190			190
Repurchase of common stock	(103)			(103)
Payments for Repurchase of Common Stock	103
Preferred dividends declared	(54)				(54)
Common dividends declared	(1,081)				(1,081)
Balance, value at Dec. 31, 2019	$ 11,041	$ 932	$ 5	$ 13,893	$ (3,886)	$ 97
Balance, Common Stock, shares at Dec. 31, 2019	540.9		540.9

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Statement of Cash Flows [Abstract]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 1,282	$ 1,520	$ 1,363
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	2,097	1,090	474
Operating activities:
Net income (loss)	688	129	771
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of premiums and discounts on mortgage-backed securities, net	601	331	378
Amortization of intangible assets	0	25	3
Stock based compensation	13	6	4
(Gain) loss on sale of investment securities, net	(388)	137	63
Unrealized (gain) loss on investment securities measured at fair value through net income, net	(2,014)	297	71
(Gain) loss on derivative instruments and other securities, net	2,324	167	(193)
(Increase) decrease in other assets	(35)	(100)	82
Increase (decrease) in accounts payable and other accrued liabilities	(9)	121	81
Net cash provided by operating activities	1,180	1,113	1,260
Investing activities:
Purchases of Agency mortgage-backed securities	(47,548)	(42,586)	(35,920)
Purchases of credit risk transfer and non-Agency securities	(1,406)	(1,572)	(1,074)
Proceeds from sale of Agency mortgage-backed securities	23,212	8,132	18,701
Proceeds from sale of credit risk transfer and non-Agency securities	1,437	891	494
Principal collections on Agency mortgage-backed securities	12,810	7,170	6,869
Principal collections on credit risk transfer and non-Agency securities	20	15	5
Payments on U.S. Treasury securities	(26,823)	(10,829)	(11,756)
Proceeds from U.S. Treasury securities	13,555	21,308	14,557
Net proceeds from (payments on) reverse repurchase agreements	11,962	(10,571)	(3,162)
Net proceeds from (payments on) derivative instruments	(1,437)	76	253
Net proceeds from other investing activity	0	30	(28)
Net cash used in investing activities	(14,218)	(27,936)	(11,061)
Financing activities:
Proceeds from repurchase arrangements	4,234,972	2,031,463	483,516
Payments on repurchase agreements	(4,221,507)	(2,006,042)	(471,078)
Payments on debt of consolidated variable interest entities	(55)	(78)	(104)
Payments on Federal Home Loan Bank advances	0	0	(3,037)
Net proceeds from preferred stock issuance	(617)	0	(315)
Payments for preferred stock redemptions	(175)	0	(173)
Net proceeds from common stock issuance	190	2,611	1,238
Payments for common stock repurchases	(103)	0	0
Cash dividends paid	(1,139)	(974)	(795)
Net cash provided by financing activities	12,800	26,980	9,882
Net change in cash and cash equivalents	(238)	157	$ 81
Cash and cash equivalents at end of period	$ 831	$ 921

Unaudited Interim Consolidated

Unaudited Interim Consolidated Financial Statements	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	Quarterly Results (Unaudited) The following is a presentation of the quarterly results of operations and comprehensive income (loss) for fiscal years 2019 and 2018 (in millions, except per share data). Quarter Ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 Interest income: Interest income $ 705 $ 693 $ 676 $ 768 Interest expense 541 570 557 481 Net interest income 164 123 119 287 Other gain (loss): Gain on sale of investment securities, net 60 132 89 107 Unrealized gain (loss) on investment securities measured at fair value through net income, net 1,060 759 355 (160 ) Gain (loss) on derivative instruments and other securities, net (1,000 ) (1,438 ) (548 ) 662 Total other gain (loss), net 120 (547 ) (104 ) 609 Expenses: Compensation and benefits 10 11 10 16 Other operating expenses 9 9 9 9 Total expenses 19 20 19 25 Net income (loss) 265 (444 ) (4 ) 871 Dividends on preferred stock 10 13 13 18 Issuance cost of redeemed preferred stock — — — 6 Net income (loss) available (attributable) to common shareholders $ 255 $ (457 ) $ (17 ) $ 847 Net income (loss) $ 265 $ (444 ) $ (4 ) $ 871 Unrealized gain on investment securities measured at fair value through other comprehensive income (loss), net 400 379 246 15 Comprehensive income (loss) 665 (65 ) 242 886 Dividends on preferred stock 10 13 13 18 Issuance cost of redeemed preferred stock — — — 6 Comprehensive income (loss) available (attributable) to common shareholders $ 655 $ (78 ) $ 229 $ 862 Weighted average number of common shares outstanding - basic 536.7 537.8 546.4 541.4 Weighted average number of common shares outstanding - diluted 537.2 537.8 546.4 542.6 Net income (loss) per common share - basic $ 0.48 $ (0.85 ) $ (0.03 ) $ 1.56 Net income (loss) per common share - diluted $ 0.47 $ (0.85 ) $ (0.03 ) $ 1.56 Comprehensive income (loss) per common share - basic $ 1.22 $ (0.15 ) $ 0.42 $ 1.59 Comprehensive income (loss) per common share - diluted $ 1.22 $ (0.15 ) $ 0.42 $ 1.59 Dividends declared per common share $ 0.54 $ 0.50 $ 0.48 $ 0.48 Quarter Ended March 31, 2018 June 30, 2018 September 30, 2018 December 31, 2018 Interest income: Interest income $ 431 $ 414 $ 500 $ 604 Interest expense 206 237 312 418 Net interest income 225 177 188 186 Other gain (loss): Loss on sale of investment securities, net (2 ) (74 ) (40 ) (21 ) Unrealized gain (loss) on investment securities measured at fair value through net income, net (523 ) (94 ) (363 ) 683 Gain (loss) on derivative instruments and other securities, net 738 298 430 (1,633 ) Management fee income 4 4 46 — Total other gain (loss), net 217 134 73 (971 ) Expenses: Compensation and benefits 10 10 14 11 Other operating expenses 8 8 31 8 Total expenses 18 18 45 19 Net income (loss) 424 293 216 (804 ) Dividends on preferred stock 9 9 9 9 Net income (loss) available (attributable) to common shareholders $ 415 $ 284 $ 207 $ (813 ) Net income (loss) $ 424 $ 293 $ 216 $ (804 ) Unrealized gain (loss) on investment securities measured at fair value through other comprehensive income (loss), net (621 ) (145 ) (193 ) 361 Comprehensive income (loss) (197 ) 148 23 (443 ) Dividends on preferred stock 9 9 9 9 Comprehensive income (loss) available (attributable) to common shareholders $ (206 ) $ 139 $ 14 $ (452 ) Weighted average number of common shares outstanding - basic 391.3 404.9 462.3 504.2 Weighted average number of common shares outstanding - diluted 391.5 405.2 462.7 504.2 Net income (loss) per common share - basic and diluted $ 1.06 $ 0.70 $ 0.45 $ (1.61 ) Comprehensive income (loss) per common share - basic and diluted $ (0.53 ) $ 0.34 $ 0.03 $ (0.90 ) Dividends declared per common share $ 0.54 $ 0.54 $ 0.54 $ 0.54

Organization

Organization	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization We were 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 are internally managed, and our principal objective is to provide 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. 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. As a REIT, we will generally not be subject to U.S. federal or state corporate taxes on our taxable income 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Consolidation Our consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States ("GAAP"). Our consolidated financial statements include the accounts of all subsidiaries and variable interest entities for which we are the primary beneficiary. Significant intercompany accounts and transactions have been eliminated. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and revenues and expenses during the period reported. Actual results could differ from those estimates. 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 gains or losses 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, as the fair value changes for these assets are presented in a manner consistent with the presentation and timing of the fair value changes of our derivative instruments. We estimate the fair value of our investment securities based on prices provided by multiple third-party pricing services and non-binding dealer quotes (collectively "pricing sources"). These pricing sources use various valuation approaches, including market and income approaches, using "Level 2" inputs. The pricing sources primarily utilize a matrix pricing technique that interpolates the estimated fair value of our Agency RMBS 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, which may include maximum loan balance, loan vintage, loan-to-value ratio, geography and other characteristics as may be appropriate. The pricing sources may also utilize discounted cash flow model-derived pricing techniques to estimate the fair value of investment securities. 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 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. We review the pricing estimates obtained from the pricing sources and perform procedures to validate their reasonableness. Refer to Note 7 for further discussion of fair value measurements. We evaluate our investments designated as available-for-sale, on a quarterly basis, to assess whether a decline in the fair value of the security below its amortized cost basis is an other-than-temporary impairment ("OTTI"). The determination of whether a security is other-than-temporarily impaired may involve judgments and assumptions based on subjective and objective factors. When a security is impaired, an OTTI is considered to have occurred if any one of the following three conditions exists as of the financial reporting date: (i) we intend to sell the security (that is, a decision has been made to sell the security), (ii) it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis or (iii) we do not expect to recover the security's amortized cost basis, even if we do not intend to sell the security and it is not more likely than not that we will be required to sell the security. A general allowance for unidentified impairments in a portfolio of securities is not permitted. If either of the first two conditions exists as of the financial reporting date, the entire amount of the impairment loss, if any, is recognized in earnings as a realized loss and the cost basis of the security is adjusted to its fair value. If the third condition exists, the OTTI is separated into (i) the amount relating to credit loss (the "credit component") and (ii) the amount relating to all other factors (the "non-credit components"). Only the credit component is recognized in earnings, with the non-credit components recognized in OCI. We did not recognize OTTI charges on our investment securities for fiscal years 2019, 2018 or 2017. 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, 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 and compare the results to market consensus prepayment speeds, if available. We also consider historical prepayment speeds and current market conditions to validate the reasonableness of the third-party estimates. 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 transactions under master repurchase agreements. Pursuant to ASC Topic 860, Transfers and Servicing , we account for repurchase transactions 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. Interest rates on our repurchase agreements generally correspond to short-term benchmark rates plus or minus a fixed spread. The fair value of our repurchase agreements is assumed to equal cost as the interest rates are considered to be at market. 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. The fair value of our reverse repurchase agreements is assumed to equal cost as the interest rates are considered to be at market. 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. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized if the counterparties to these instruments fail to perform their obligations under the contracts. Our derivative agreements require that we post or receive collateral to mitigate such risk. We also attempt to minimize our risk of loss by limiting our counterparties to registered central clearing exchanges and major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. 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 three-month London Interbank Offered Rate ("LIBOR"), Overnight Index Swap Rate ("OIS") or Secured Overnight Financing Rate ("SOFR"). Our interest rate swaps typically have terms from one to 10 years but may extend up to 20 years or more. The majority of our interest rate swaps are centrally cleared through a registered commodities exchange. We value centrally cleared interest rate swaps 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. Our centrally cleared swaps require that we post an "initial margin" amount determined by the clearing 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. We value non-centrally cleared swaps using a combination of third-party valuations obtained from pricing services and the swap counterparty. The third-party valuations are model-driven using observable inputs, including short-term benchmark rates, swap rates and the forward yield curve. We also consider both our own and our counterparties' nonperformance risk in estimating the fair value of our interest rate swaps. In considering the effect of nonperformance risk, we assess the impact of netting and credit enhancements, such as collateral postings and guarantees, and have concluded that our own and our counterparty risk is not significant to the overall valuation of these agreements. 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. We estimate the fair value of interest rate swaptions using a combination of inputs from counterparty and third-party pricing models based on the fair 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, adjusted for non-performance risk, if any. 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. We estimate the fair value of TBA securities based on similar methods used to value our Agency RMBS securities. 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. Consolidated Variable Interest Entities ASC Topic 810, Consolidation ("ASC 810"), requires an enterprise to consolidate a variable interest entity ("VIE") if it is deemed the primary beneficiary of the VIE. As of December 31, 2019 and 2018 , our consolidated financial statements reflect the consolidation of certain VIEs for which we have determined we are the primary beneficiary. The consolidated VIEs consist of CMO trusts backed by fixed or adjustable-rate Agency RMBS. Fannie Mae or Freddie Mac guarantees the payment of interest and principal and acts as the trustee and administrator of their respective securitization trusts. Accordingly, we are not required to provide the beneficial interest holders of the CMO securities any financial or other support. Our maximum exposure to loss related to our involvement with the CMO trusts is the fair value of the CMO securities and interest and principal-only securities held by us, less principal amounts guaranteed by Fannie Mae and Freddie Mac. We elected the option to account for the debt of consolidated VIEs at fair value, with changes in fair value reflected in earnings during the period in which they occur. We believe this election more appropriately reflects our financial position as both the consolidated assets and consolidated debt are presented in a consistent manner on our consolidated balance sheets. We estimate the fair value of the consolidated debt based on the fair value of the Agency RMBS held by the CMO trusts, less the fair value of our retained interests in the trusts, which are measured on a market approach using "Level 2" inputs from third-party pricing services and dealer quotes, because such inputs are more observable than inputs to otherwise independently determine the value of our consolidated debt. Cash and Cash Equivalents Cash and cash equivalents include cash held in bank accounts and cash held in money market funds on an overnight basis. Restricted Cash Restricted cash includes cash pledged as collateral for clearing and executing trades, repurchase agreements and other borrowings, and interest rate swaps and other derivative instruments. Goodwill Goodwill is the cost of an acquisition in excess of the fair value of identified assets acquired and liabilities assumed and is recognized as an asset on our consolidated balance sheets. As of December 31, 2019 and 2018, we had $526 million of goodwill related to our acquisition of AGNC Management, LLC, our former manager, on July 1, 2016. Goodwill is not subject to amortization but must be tested for impairment at least annually and at interim periods when events or circumstances may make it more likely than not that an impairment has occurred. If a qualitative analysis indicates that there may be an impairment, a quantitative analysis is performed. The quantitative analysis requires that we compare the carrying value of the identified reporting unit comprising the goodwill to the reporting unit's fair value. If the reporting units' carrying value is greater than its fair value, an impairment charge is recognized to the extent the carrying amount of the reporting unit exceeds its fair value. During fiscal years 2019, 2018, and 2017, we did not recognize a goodwill impairment charge. Stock-Based Compensation Under our 2016 AGNC Investment Corp. Equity and Incentive Compensation Plan (the "2016 Equity Plan" or "the Plan"), we may grant equity-based compensation to our officers and other employees and non-employee directors for the purpose of providing incentives and rewards for service or performance. Stock-based awards issued under the Plan include time-based and performance-based restricted stock unit awards ("RSU" and "PSU" awards, respectively), but may include other forms of equity-based compensation. RSU and PSU awards are an agreement to issue an equivalent number of shares of our common stock, plus any equivalent shares for dividends declared on our common stock, at the time the award vests, or later if distribution of such shares has been deferred beyond the vesting date. RSU awards vest over a specified service period. PSU awards vest over a specified service period subject to achieving long-term performance criteria. We measure and recognize compensation expense for all stock-based payment awards made to employees and non-employee directors based on their fair values. We value RSU and PSU awards based on the fair value of our common stock on the date of grant. Compensation expense is recognized over each award’s respective service period. In the case of PSU awards, we estimate the probability that the performance criteria will be achieved and recognize expense only for those awards expected to vest. We reevaluate our estimates each reporting period and recognize a cumulative effect adjustment to expense if our estimates change from the prior period. We do not estimate forfeiture rates; rather, we adjust for forfeitures in the periods in which they occur. Shares underlying RSU and PSU awards are issued on the vesting dates, or later if distribution of such shares has been deferred beyond the vesting date, net of shares withheld for minimum statutory tax withholdings to be paid by us on behalf of our employees. As a result, the actual number of shares issued will be fewer than the actual number of awards outstanding. When shares are withheld for statutory tax withholdings, we record a liability for tax withholding amounts to be paid by us as a reduction to additional paid-in capital. Recent Accounting Pronouncements We consider the applicability and impact of all Accounting Standards Updates ("ASUs") issued by the Financial Accounting Standards Board. ASUs not listed below were determined to be either not applicable, are not expected to have a significant impact on our consolidated financial statements when adopted or did not have a significant impact on our consolidated financial statements upon adoption. ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. Under ASU 2016-13, credit losses on available-for-sale investment securities are recorded as an allowance rather than as a direct reduction of amortized cost. Remaining losses unrelated to credit loss, such as due to changing interest rates, continue to be recorded through OCI. The new model also requires the estimation of lifetime expected credit losses and corresponding recognition of allowance for losses on trade and other receivables, held-to-maturity debt securities, loans, and other instruments held at amortized cost. The ASU requires certain recurring disclosures and is effective for annual periods, and interim periods within those annual periods, beginning on or after December 15, 2019. ASU 2016-13 is not expected to have a significant impact on our consolidated financial statements.

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investment Securities	3 years and ≤ 5 years 10,822 10,563 3.85% 3.20% 5,518 5,586 3.35% 2.73% > 5 years and ≤10 years 86,492 85,002 3.67% 3.07% 72,503 73,588 3.92% 3.37% > 10 years 457 451 3.31% 3.06% 4,576 4,679 3.57% 3.30% Total $ 100,442 $ 98,670 3.68% 3.07% $ 84,287 $ 85,569 3.86% 3.31% The following table presents the gross unrealized loss and fair values of securities classified as available-for-sale by length of time that such securities have been in a continuous unrealized loss position as of December 31, 2019 and 2018 (in millions): Unrealized Loss Position For Less than 12 Months 12 Months or More Total Securities Classified as Available-for-Sale Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss December 31, 2019 $ 1,653 $ (12 ) $ 6,984 $ (63 ) $ 8,637 $ (75 ) December 31, 2018 $ 4,783 $ (72 ) $ 18,231 $ (878 ) $ 23,014 $ (950 ) We did not recognize OTTI charges on our investment securities classified as available-for-sale during the periods presented on our consolidated statements of operations. As of the end of each respective reporting period, a decision had not been made to sell securities in an unrealized loss position and we did not believe it was more likely than not that we would be required to sell such securities before recovery of their amortized cost basis. 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 fiscal years 2019, 2018 and 2017 by investment classification of accounting (in millions): Fiscal Year 2019 Fiscal Year 2018 Fiscal Year 2017 Investment Securities Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale 2 Fair Value Option Securities Total Investment securities sold, at cost $ (732 ) $ (23,040 ) $ (23,772 ) $ (4,306 ) $ (5,344 ) $ (9,650 ) $ (6,324 ) $ (12,913 ) $ (19,237 ) Proceeds from investment securities sold 1 723 23,437 24,160 4,227 5,286 9,513 6,241 12,933 19,174 Net gain (loss) on sale of investment securities $ (9 ) $ 397 $ 388 $ (79 ) $ (58 ) $ (137 ) $ (83 ) $ 20 $ (63 ) Gross gain on sale of investment securities $ — $ 401 $ 401 $ 6 $ 16 $ 22 $ 16 $ 48 $ 64 Gross loss on sale of investment securities (9 ) (4 ) (13 ) (85 ) (74 ) (159 ) (99 ) (28 ) (127 ) Net gain (loss) on sale of investment securities $ (9 ) $ 397 $ 388 $ (79 ) $ (58 ) $ (137 ) $ (83 ) $ 20 $ (63 ) ________________________________ 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" id="sjs-B4">Investment Securities As of December 31, 2019 and 2018 , our investment portfolio consisted of $100.4 billion and $84.3 billion of investment securities, at fair value, respectively, and $7.4 billion and $7.3 billion of net TBA securities, at fair value, respectively. Our net TBA position is reported at its net carrying value of $25 million and $70 million as of December 31, 2019 and 2018 , respectively, in derivative assets / (liabilities) on our accompanying consolidated balance sheets. The net carrying value of our TBA position represents the difference between the fair value of the underlying Agency security in the TBA contract and the cost basis or the forward price to be paid or received for the underlying Agency security. As of December 31, 2019 and 2018 , our investment securities had a net unamortized premium balance of $3.1 billion and $2.9 billion , respectively. The following tables summarize our investment securities as of December 31, 2019 and 2018 , excluding TBA securities, (dollars in millions). Details of our TBA securities as of each of the respective dates are included in Note 5 . December 31, 2019 December 31, 2018 Investment Securities Amortized Cost Fair Value Amortized Fair Value Agency RMBS: Fixed rate $ 96,375 $ 98,074 $ 83,047 $ 81,753 Adjustable rate 160 163 212 213 CMO 441 447 588 583 Interest-only and principal-only strips 146 164 172 178 Multifamily 37 39 — — Total Agency RMBS 97,159 98,887 84,019 82,727 Non-Agency RMBS 198 209 264 266 CMBS 352 370 280 282 CRT securities 961 976 1,006 1,012 Total investment securities $ 98,670 $ 100,442 $ 85,569 $ 84,287 December 31, 2019 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 14,301 $ 4,762 $ 18 $ — $ — $ — $ 19,081 Unamortized discount (10 ) (2 ) — — — — (12 ) Unamortized premium 711 276 — — — — 987 Amortized cost 15,002 5,036 18 — — — 20,056 Gross unrealized gains 142 29 1 — — — 172 Gross unrealized losses (50 ) (25 ) — — — — (75 ) Total available-for-sale securities, at fair value 15,094 5,040 19 — — — 20,153 Securities remeasured at fair value through earnings: Par value 45,106 29,881 — 208 348 937 76,480 Unamortized discount (68 ) (2 ) — (10 ) (3 ) (2 ) (85 ) Unamortized premium 1,218 967 — 1 7 26 2,219 Amortized cost 46,256 30,846 — 199 352 961 78,614 Gross unrealized gains 991 691 — 10 19 18 1,729 Gross unrealized losses (32 ) (18 ) — — (1 ) (3 ) (54 ) Total securities remeasured at fair value through earnings 47,215 31,519 — 209 370 976 80,289 Total securities, at fair value $ 62,309 $ 36,559 $ 19 $ 209 $ 370 $ 976 $ 100,442 Weighted average coupon as of December 31, 2019 3.62 % 3.75 % 3.77 % 4.05 % 4.49 % 5.07 % 3.68 % Weighted average yield as of December 31, 2019 1 3.03 % 3.09 % 2.08 % 4.39 % 4.38 % 4.05 % 3.07 % ________________________________ 1. Incorporates a weighted average future constant prepayment rate assumption of 10.8% based on forward rates as of December 31, 2019 . December 31, 2018 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 17,591 $ 5,673 $ 25 $ 6 $ — $ — $ 23,295 Unamortized discount (10 ) (2 ) — — — — (12 ) Unamortized premium 912 343 — — — — 1,255 Amortized cost 18,493 6,014 25 6 — — 24,538 Gross unrealized gains 4 2 1 — — — 7 Gross unrealized losses (686 ) (264 ) — — — — (950 ) Total available-for-sale securities, at fair value 17,811 5,752 26 6 — — 23,595 Securities remeasured at fair value through earnings: Par value 39,453 18,428 — 268 281 968 59,398 Unamortized discount (78 ) (9 ) — (10 ) (6 ) — (103 ) Unamortized premium 1,055 638 — — 5 38 1,736 Amortized cost 40,430 19,057 — 258 280 1,006 61,031 Gross unrealized gains 223 57 — 2 3 18 303 Gross unrealized losses (386 ) (243 ) — — (1 ) (12 ) (642 ) Total securities remeasured at fair value through earnings 40,267 18,871 — 260 282 1,012 60,692 Total securities, at fair value $ 58,078 $ 24,623 $ 26 $ 266 $ 282 $ 1,012 $ 84,287 Weighted average coupon as of December 31, 2018 3.82 % 3.87 % 3.37 % 3.83 % 4.58 % 5.86 % 3.86 % Weighted average yield as of December 31, 2018 1 3.28 % 3.28 % 2.04 % 4.22 % 4.68 % 5.16 % 3.31 % ________________________________ 1. Incorporates a weighted average future constant prepayment rate assumption of 7.9% based on forward rates as of December 31, 2018 . As of December 31, 2019 and 2018 , our investments in CRT and non-Agency securities had the following credit ratings: December 31, 2019 December 31, 2018 CRT and Non-Agency Security Credit Ratings 1 CRT RMBS CMBS CRT RMBS CMBS AAA $ — $ — $ 43 $ — $ 160 $ 52 AA — 81 214 — 17 152 A 13 25 34 17 33 15 BBB 67 71 69 25 43 53 BB 471 21 10 492 8 10 B 308 4 — 453 2 — Not Rated 117 7 — 25 3 — Total $ 976 $ 209 $ 370 $ 1,012 $ 266 $ 282 ________________________________ 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 December 31, 2019 and 2018 , 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 10.8% and 7.9% , 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 December 31, 2019 and 2018 according to their estimated weighted average life classification (dollars in millions): December 31, 2019 December 31, 2018 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 $ 2,671 $ 2,654 3.54% 2.61% $ 1,690 $ 1,716 3.99% 2.64% > 3 years and ≤ 5 years 10,822 10,563 3.85% 3.20% 5,518 5,586 3.35% 2.73% > 5 years and ≤10 years 86,492 85,002 3.67% 3.07% 72,503 73,588 3.92% 3.37% > 10 years 457 451 3.31% 3.06% 4,576 4,679 3.57% 3.30% Total $ 100,442 $ 98,670 3.68% 3.07% $ 84,287 $ 85,569 3.86% 3.31% The following table presents the gross unrealized loss and fair values of securities classified as available-for-sale by length of time that such securities have been in a continuous unrealized loss position as of December 31, 2019 and 2018 (in millions): Unrealized Loss Position For Less than 12 Months 12 Months or More Total Securities Classified as Available-for-Sale Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss December 31, 2019 $ 1,653 $ (12 ) $ 6,984 $ (63 ) $ 8,637 $ (75 ) December 31, 2018 $ 4,783 $ (72 ) $ 18,231 $ (878 ) $ 23,014 $ (950 ) We did not recognize OTTI charges on our investment securities classified as available-for-sale during the periods presented on our consolidated statements of operations. As of the end of each respective reporting period, a decision had not been made to sell securities in an unrealized loss position and we did not believe it was more likely than not that we would be required to sell such securities before recovery of their amortized cost basis. 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 fiscal years 2019, 2018 and 2017 by investment classification of accounting (in millions): Fiscal Year 2019 Fiscal Year 2018 Fiscal Year 2017 Investment Securities Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale 2 Fair Value Option Securities Total Investment securities sold, at cost $ (732 ) $ (23,040 ) $ (23,772 ) $ (4,306 ) $ (5,344 ) $ (9,650 ) $ (6,324 ) $ (12,913 ) $ (19,237 ) Proceeds from investment securities sold 1 723 23,437 24,160 4,227 5,286 9,513 6,241 12,933 19,174 Net gain (loss) on sale of investment securities $ (9 ) $ 397 $ 388 $ (79 ) $ (58 ) $ (137 ) $ (83 ) $ 20 $ (63 ) Gross gain on sale of investment securities $ — $ 401 $ 401 $ 6 $ 16 $ 22 $ 16 $ 48 $ 64 Gross loss on sale of investment securities (9 ) (4 ) (13 ) (85 ) (74 ) (159 ) (99 ) (28 ) (127 ) Net gain (loss) on sale of investment securities $ (9 ) $ 397 $ 388 $ (79 ) $ (58 ) $ (137 ) $ (83 ) $ 20 $ (63 ) ________________________________ 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

Repurchase Agreements And Rever

Repurchase Agreements And Reverse Repurchase Agreements	12 Months Ended
	Dec. 31, 2019
Disclosure of Repurchase Agreements [Abstract]
Repurchase Agreements And Other Debt	1 to ≤ 3 months 20,761 2.01 % 53 20,991 2.57 % 56 > 3 to ≤ 6 months 5,683 2.19 % 100 2,218 2.65 % 167 > 6 to ≤ 9 months 1,500 2.66 % 182 200 3.19 % 208 > 9 to ≤ 12 months 2,152 2.41 % 351 950 2.80 % 279 > 12 to ≤ 24 months 625 2.38 % 411 2,200 2.91 % 438 > 24 to ≤ 36 months 1,700 2.45 % 833 625 3.11 % 776 Total Agency repo 89,085 2.17 % 55 75,717 2.79 % 49 U.S. Treasury repo: > 1 day to ≤ 1 month 97 1.63 % 2 — — % — Total $ 89,182 2.17 % 55 $ 75,717 2.79 % 49 As of December 31, 2019 and 2018 , $17.0 billion and $19.5 billion , respectively, of our repurchase agreements had a remaining maturity of one business day and none of our repurchase agreements were due on demand. As of December 31, 2019 , we had $4.5 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 12 days and a weighted average interest rate of 1.60% . As of 2018 we had $10.7 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 9 days and a weighted average interest rate of 2.90% . As of December 31, 2019 and 2018 , 40% and 35% , 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 38% and 33% of our repurchase agreement funding outstanding as of December 31, 2019 and 2018 , respectively. Reverse Repurchase Agreements As of December 31, 2019 and 2018 , we had $10.2 billion and $21.8 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 $9.5 billion and $21.4 billion , respectively. As of December 31, 2019 and 2018 , $5.4 billion and $4.5 billion" id="sjs-B4">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 December 31, 2019 , we had met all margin call requirements. For additional information regarding our pledged assets, please refer to Note 6 . As of December 31, 2019 and 2018 , we had $89.2 billion and $75.7 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 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 December 31, 2019 and 2018 (dollars in millions): December 31, 2019 December 31, 2018 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 $ 56,664 2.19 % 10 $ 48,533 2.88 % 9 > 1 to ≤ 3 months 20,761 2.01 % 53 20,991 2.57 % 56 > 3 to ≤ 6 months 5,683 2.19 % 100 2,218 2.65 % 167 > 6 to ≤ 9 months 1,500 2.66 % 182 200 3.19 % 208 > 9 to ≤ 12 months 2,152 2.41 % 351 950 2.80 % 279 > 12 to ≤ 24 months 625 2.38 % 411 2,200 2.91 % 438 > 24 to ≤ 36 months 1,700 2.45 % 833 625 3.11 % 776 Total Agency repo 89,085 2.17 % 55 75,717 2.79 % 49 U.S. Treasury repo: > 1 day to ≤ 1 month 97 1.63 % 2 — — % — Total $ 89,182 2.17 % 55 $ 75,717 2.79 % 49 As of December 31, 2019 and 2018 , $17.0 billion and $19.5 billion , respectively, of our repurchase agreements had a remaining maturity of one business day and none of our repurchase agreements were due on demand. As of December 31, 2019 , we had $4.5 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 12 days and a weighted average interest rate of 1.60% . As of 2018 we had $10.7 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 9 days and a weighted average interest rate of 2.90% . As of December 31, 2019 and 2018 , 40% and 35% , 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 38% and 33% of our repurchase agreement funding outstanding as of December 31, 2019 and 2018 , respectively. Reverse Repurchase Agreements As of December 31, 2019 and 2018 , we had $10.2 billion and $21.8 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 $9.5 billion and $21.4 billion , respectively. As of December 31, 2019 and 2018 , $5.4 billion and $4.5 billion

Derivative and Other Hedging In

Derivative and Other Hedging Instruments	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
US Government Futures Securities [Table Text Block]	U.S. Treasury Futures December 31, 2019 December 31, 2018 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 $ (1,000 ) $ (1,298 ) $ (1,284 ) $ 14 $ (1,650 ) $ (1,969 ) $ (2,013 ) $ (44 ) ________________________________ 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 Instruments We 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 December 31, 2019 and 2018 (in millions): December 31, Derivative and Other Hedging Instruments Balance Sheet Location 2019 2018 Interest rate swaps Derivative assets, at fair value $ 21 $ 126 Swaptions Derivative assets, at fair value 126 37 TBA securities Derivative assets, at fair value 29 110 U.S. Treasury futures - short Derivative assets, at fair value 14 — Total derivative assets, at fair value $ 190 $ 273 Interest rate swaps Derivative liabilities, at fair value $ (2 ) $ — TBA securities Derivative liabilities, at fair value (4 ) (40 ) U.S. Treasury futures - short Derivative liabilities, at fair value — (44 ) Total derivative liabilities, at fair value $ (6 ) $ (84 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ 97 $ 46 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (9,543 ) (21,431 ) Total U.S. Treasury securities, net at fair value $ (9,446 ) $ (21,385 ) The following tables summarize certain characteristics of our derivative and other hedging instruments outstanding as of December 31, 2019 and 2018 (dollars in millions): December 31, 2019 December 31, 2018 Pay Fixed / Receive Variable Interest Rate Swaps Notional Average Rate Average Average Notional 1 Average Rate 2 Average Average ≤ 3 years $ 59,700 1.30% 1.58% 1.6 $ 19,900 1.63% 2.62% 1.3 > 3 to ≤ 5 years 9,850 1.17% 1.55% 3.8 8,425 2.06% 2.61% 4.0 > 5 to ≤ 7 years 5,650 1.34% 1.70% 6.4 7,875 2.66% 2.66% 6.1 > 7 to ≤ 10 years 2,850 1.36% 1.58% 8.9 10,550 2.36% 2.64% 8.8 > 10 years 1,025 1.64% 1.78% 15.4 4,875 2.77% 2.63% 11.6 Total $ 79,075 1.29% 1.59% 2.7 $ 51,625 2.11% 2.63% 5.0 ________________________________ 1. Notional amount as of December 31, 2018 includes forward starting swaps of $5.7 billion with an average forward start date of 0.5 years. There were no forward starting swaps outstanding as of December 31, 2019. 2. Average fixed pay rate as of December 31, 2018 includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.98% as of 2018 . Pay Fixed / Receive Variable Interest Rate Swaps by Receive Index (% of Notional Amount) December 31, 2019 December 31, 2018 OIS 86 % — % 3M LIBOR 11 % 100 % SOFR 3 % — % 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 Average Receive Rate (LIBOR) Average Term (Years) December 31, 2019 ≤ 1 year $ 123 $ 80 8 $ 5,650 2.26% 3M 9.3 > 1 year ≤ 2 years 53 46 16 3,200 2.50% 3M 10.0 Total $ 176 $ 126 11 $ 8,850 2.34% 3M 9.5 December 31, 2018 ≤ 1 year $ 80 $ 23 4 $ 3,000 2.96% 3M 7.0 > 1 year ≤ 2 years 18 14 18 500 2.78% 3M 10.0 Total $ 98 $ 37 6 $ 3,500 2.93% 3M 7.4 ________________________________ 1. As of December 31, 2019 and 2018 , ≤ 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. U.S. Treasury Securities December 31, 2019 December 31, 2018 Maturity Face Amount Long/(Short) Cost Basis 1 Fair Value Face Amount Long/(Short) Cost Basis 1 Fair Value 5 years $ 95 $ 95 $ 97 $ (703 ) $ (706 ) $ (713 ) 7 years — — — (14,357 ) (14,325 ) (14,410 ) 10 years (9,224 ) (9,329 ) (9,543 ) (6,240 ) (6,224 ) (6,262 ) Total U.S. Treasury securities $ (9,129 ) $ (9,234 ) $ (9,446 ) $ (21,300 ) $ (21,255 ) $ (21,385 ) ________________________________ 1. As of December 31, 2019 and 2018 , short U.S. Treasury securities had a weighted average yield of 2.19% and 2.66% , respectively, and long U.S. Treasury securities had a weighted average yield of 2.21% and 2.98% , respectively. U.S. Treasury Futures December 31, 2019 December 31, 2018 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 $ (1,000 ) $ (1,298 ) $ (1,284 ) $ 14 $ (1,650 ) $ (1,969 ) $ (2,013 ) $ (44 ) ________________________________ 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. December 31, 2019 December 31, 2018 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: 2.5% $ 805 $ 811 $ 812 $ 1 $ — $ — $ — $ — 3.0% 1,059 1,083 1,086 3 567 557 566 9 3.5% 241 250 250 — 1,706 1,708 1,726 18 4.0% 75 78 78 — 1,350 1,370 1,381 11 Total 15-Year TBA securities 2,180 2,222 2,226 4 3,623 3,635 3,673 38 30-Year TBA securities: ≤3.0% 5,008 5,052 5,073 21 1,028 981 1,003 22 3.5% 1,226 1,259 1,261 2 (2,979 ) (2,943 ) (2,977 ) (34 ) 4.0% (1,507 ) (1,565 ) (1,568 ) (3 ) 3,030 3,073 3,089 16 ≥ 4.5% 415 436 437 1 2,450 2,506 2,534 28 Total 30-Year TBA securities, net 5,142 5,182 5,203 21 3,529 3,617 3,649 32 Total TBA securities, net $ 7,322 $ 7,404 $ 7,429 $ 25 $ 7,152 $ 7,252 $ 7,322 $ 70 ________________________________ 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 fiscal years 2019, 2018 and 2017 (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 Fiscal Year 2019: TBA securities, net $ 7,152 95,169 (94,999 ) $ 7,322 $ 411 Interest rate swaps - payer $ 51,625 166,975 (139,525 ) $ 79,075 (1,645 ) Interest rate swaps - receiver $ — (175 ) 175 $ — — Payer swaptions $ 3,500 7,650 (2,300 ) $ 8,850 (26 ) U.S. Treasury securities - short position $ (21,345 ) (12,601 ) 24,722 $ (9,224 ) (967 ) U.S. Treasury securities - long position $ 45 1,776 (1,726 ) $ 95 11 U.S. Treasury futures contracts - short position $ (1,650 ) (5,300 ) 5,950 $ (1,000 ) (109 ) $ (2,325 ) Fiscal Year 2018: TBA securities, net $ 15,474 194,534 (202,856 ) $ 7,152 $ (299 ) Interest rate swaps $ 43,700 14,350 (6,425 ) $ 51,625 140 Payer swaptions $ 6,650 1,250 (4,400 ) $ 3,500 90 U.S. Treasury securities - short position $ (10,699 ) (19,278 ) 8,632 $ (21,345 ) (161 ) U.S. Treasury securities - long position $ — 1,949 (1,904 ) $ 45 1 U.S. Treasury futures contracts - short position $ (2,910 ) (7,859 ) 9,119 $ (1,650 ) 48 $ (181 ) Fiscal Year 2017: TBA securities, net $ 10,916 237,601 (233,043 ) $ 15,474 $ 330 Interest rate swaps $ 37,175 14,825 (8,300 ) $ 43,700 67 Payer swaptions $ 1,200 6,450 (1,000 ) $ 6,650 (66 ) U.S. Treasury securities - short position $ (8,061 ) (14,030 ) 11,392 $ (10,699 ) (141 ) U.S. Treasury securities - long position $ 189 404 (593 ) $ — 1 U.S. Treasury futures contracts - short position $ (1,810 ) (11,340 ) 10,240 $ (2,910 ) — $ 191 ________________________________ 1.

Pledged Assets

Pledged Assets	12 Months Ended
	Dec. 31, 2019
Pledged Assets [Abstract]
Pledged Assets	30 and ≤ 60 days 14,410 14,114 42 14,586 14,810 46 > 60 and ≤ 90 days 7,637 7,536 20 7,770 7,843 24 > 90 days 13,510 13,286 38 6,882 7,079 21 Total $ 92,547 $ 90,887 $ 267 $ 79,182 $ 80,386 $ 247 ________________________________ 1. Includes $144 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of December 31, 2019 and 2018 , respectively. 2. Excludes $357 million and $437 million of repledged U.S. Treasury securities received as collateral from counterparties as of December 31, 2019 and 2018 , respectively. Assets Pledged from Counterparties As of December 31, 2019 and 2018 , we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions). December 31, 2019 December 31, 2018 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 $ 10,099 $ — $ 1 $ 10,100 $ 21,876 $ 35 $ 37 $ 21,948 Cash — 116 — 116 — 129 — 129 Total $ 10,099 $ 116 $ 1 $ 10,216 $ 21,876 $ 164 $ 37 $ 22,077 ________________________________ 1. As of December 31, 2019 and 2018 , $357 million and $437 million , respectively, of U.S. Treasury securities received from counterparties were repledged as collateral and $9.5 billion and $21.4 billion, respectively, were used to cover short sales of U.S. Treasury securities. 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 December 31, 2019 and 2018 (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 December 31, 2019 Interest rate swap and swaption agreements, at fair value 1 $ 147 $ — $ 147 $ (2 ) $ (116 ) $ 29 TBA securities, at fair value 29 — 29 (4 ) — 25 Receivable under reverse repurchase agreements 10,181 — 10,181 (9,852 ) (329 ) — Total $ 10,357 $ — $ 10,357 $ (9,858 ) $ (445 ) $ 54 December 31, 2018 Interest rate swap and swaption agreements, at fair value 1 $ 163 $ — $ 163 $ — $ (158 ) $ 5 TBA securities, at fair value 110 — 110 (40 ) — 70 Receivable under reverse repurchase agreements 21,813 — 21,813 (17,236 ) (4,575 ) 2 Total $ 22,086 $ — $ 22,086 $ (17,276 ) $ (4,733 ) $ 77 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 December 31, 2019 Interest rate swap agreements, at fair value 1 $ 2 $ — $ 2 $ (2 ) $ — $ — TBA securities, at fair value 4 — 4 (4 ) — — Repurchase agreements 89,182 — 89,182 (9,852 ) (79,330 ) — Total $ 89,188 $ — $ 89,188 $ (9,858 ) $ (79,330 ) $ — December 31, 2018 Interest rate swap agreements, at fair value 1 $ — $ — $ — $ — $ — $ — TBA securities, at fair value 40 — 40 (40 ) — — Repurchase agreements 75,717 — 75,717 (17,236 ) (58,481 ) — Total $ 75,757 $ — $ 75,757 $ (17,276 ) $ (58,481 ) $ — ________________________________ 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." id="sjs-B4">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 December 31, 2019 , our maximum amount at risk with any counterparty related to our repurchase agreements, excluding the Fixed Income Clearing Corporation, was less than 4% of our tangible stockholders' equity (measured as the excess of the value of collateral pledged over the amount of our repurchase liabilities). As of December 31, 2019 , approximately 10% of our tangible stockholder's equity was at risk with the Fixed Income Clearing Corporation. Assets Pledged to Counterparties 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 December 31, 2019 and 2018 (in millions): December 31, 2019 Assets Pledged to Counterparties 1 Repurchase Agreements 2 Debt of Consolidated VIEs Derivative Agreements Brokerage and Clearing Agreements 3 Total Agency RMBS - fair value $ 92,142 $ 371 $ 404 $ 206 $ 93,123 CRT - fair value 309 — — — 309 U.S. Treasury securities - fair value 453 — — 28 481 Accrued interest on pledged securities 267 1 1 1 270 Restricted cash and cash equivalents 111 — 340 — 451 Total $ 93,282 $ 372 $ 745 $ 235 $ 94,634 December 31, 2018 Assets Pledged to Counterparties 1 Repurchase Agreements 2 Debt of Consolidated VIEs Derivative Agreements Brokerage and Clearing Agreements 3 Total Agency RMBS - fair value $ 78,997 $ 436 $ 174 $ 133 $ 79,740 CRT - fair value 141 — — — 141 Non-Agency - fair value 45 — — — 45 U.S. Treasury securities - fair value 437 — — — 437 Accrued interest on pledged securities 246 1 1 — 248 Restricted cash and cash equivalents 77 — 522 — 599 Total $ 79,943 $ 437 $ 697 $ 133 $ 81,210 ________________________________ 1. Includes repledged assets received as collateral from counterparties. 2. Includes $144 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of December 31, 2019 and 2018 , respectively. 3. Includes margin for TBAs cleared through prime brokers and other clearing deposits. 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 December 31, 2019 and 2018 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 4 . December 31, 2019 December 31, 2018 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 $ 56,990 $ 55,951 $ 167 $ 49,944 $ 50,654 $ 156 > 30 and ≤ 60 days 14,410 14,114 42 14,586 14,810 46 > 60 and ≤ 90 days 7,637 7,536 20 7,770 7,843 24 > 90 days 13,510 13,286 38 6,882 7,079 21 Total $ 92,547 $ 90,887 $ 267 $ 79,182 $ 80,386 $ 247 ________________________________ 1. Includes $144 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of December 31, 2019 and 2018 , respectively. 2. Excludes $357 million and $437 million of repledged U.S. Treasury securities received as collateral from counterparties as of December 31, 2019 and 2018 , respectively. Assets Pledged from Counterparties As of December 31, 2019 and 2018 , we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions). December 31, 2019 December 31, 2018 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 $ 10,099 $ — $ 1 $ 10,100 $ 21,876 $ 35 $ 37 $ 21,948 Cash — 116 — 116 — 129 — 129 Total $ 10,099 $ 116 $ 1 $ 10,216 $ 21,876 $ 164 $ 37 $ 22,077 ________________________________ 1. As of December 31, 2019 and 2018 , $357 million and $437 million , respectively, of U.S. Treasury securities received from counterparties were repledged as collateral and $9.5 billion and $21.4 billion, respectively, were used to cover short sales of U.S. Treasury securities. 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 December 31, 2019 and 2018 (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 December 31, 2019 Interest rate swap and swaption agreements, at fair value 1 $ 147 $ — $ 147 $ (2 ) $ (116 ) $ 29 TBA securities, at fair value 29 — 29 (4 ) — 25 Receivable under reverse repurchase agreements 10,181 — 10,181 (9,852 ) (329 ) — Total $ 10,357 $ — $ 10,357 $ (9,858 ) $ (445 ) $ 54 December 31, 2018 Interest rate swap and swaption agreements, at fair value 1 $ 163 $ — $ 163 $ — $ (158 ) $ 5 TBA securities, at fair value 110 — 110 (40 ) — 70 Receivable under reverse repurchase agreements 21,813 — 21,813 (17,236 ) (4,575 ) 2 Total $ 22,086 $ — $ 22,086 $ (17,276 ) $ (4,733 ) $ 77 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 December 31, 2019 Interest rate swap agreements, at fair value 1 $ 2 $ — $ 2 $ (2 ) $ — $ — TBA securities, at fair value 4 — 4 (4 ) — — Repurchase agreements 89,182 — 89,182 (9,852 ) (79,330 ) — Total $ 89,188 $ — $ 89,188 $ (9,858 ) $ (79,330 ) $ — December 31, 2018 Interest rate swap agreements, at fair value 1 $ — $ — $ — $ — $ — $ — TBA securities, at fair value 40 — 40 (40 ) — — Repurchase agreements 75,717 — 75,717 (17,236 ) (58,481 ) — Total $ 75,757 $ — $ 75,757 $ (17,276 ) $ (58,481 ) $ — ________________________________ 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.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We determine the fair value of our 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 typically obtain price estimates from multiple third-party pricing services and dealers or, if applicable, the clearing exchange (see Note 2 for further details.) We utilize a three-level valuation hierarchy for disclosure of fair value measurements. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. A financial instrument's categorization within the hierarchy is 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 availability of observable inputs can vary by instrument and is 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. Third-party pricing sources may also use certain unobservable inputs, such as assumptions of future levels of prepayment, defaults and loss severities, especially when estimating fair values for securities with lower levels of recent trading activity. We make inquiries of third-party pricing sources to understand the significant inputs and assumptions they used to determine their prices. 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 validation procedures described above also influence our determination of the appropriate fair value measurement categorization. The following table provides a summary of our assets and liabilities that are measured at fair value on a recurring basis, as of December 31, 2019 and 2018 , based on their categorization within the valuation hierarchy (in millions). There were no transfers between valuation hierarchy levels during the periods presented. December 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 98,516 $ — $ — $ 82,291 $ — Agency securities transferred to consolidated VIEs — 371 — — 436 — Credit risk transfer securities — 976 — — 1,012 — Non-Agency securities — 579 — — 548 — U.S. Treasury securities 97 — — 46 — — Interest rate swaps — 21 — — 126 — Swaptions — 126 — — 37 — TBA securities — 29 — — 110 — U.S. Treasury futures 14 — — — — — Total $ 111 $ 100,618 $ — $ 46 $ 84,560 $ — Liabilities: Debt of consolidated VIEs $ — $ 228 $ — $ — $ 275 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 9,543 — — 21,431 — — Interest rate swaps — 2 — — — — TBA securities — 4 — — 40 — U.S. Treasury futures — — — 44 — — Total $ 9,543 $ 234 $ — $ 21,475 $ 315 $ — Excluded from the table above are financial instruments, including cash and cash equivalents, restricted cash and cash equivalents, receivables, payables and borrowings under repurchase agreements, which are presented in our consolidated financial statements at cost. The cost basis of these instruments is determined to approximate fair value due to their short duration or, in the case of longer-term repo, due to floating rates of interest corresponding on an index plus or minus a fixed spread which is consistent with fixed spreads demanded in the market. We estimate the fair value of these instruments using "Level 1" or "Level 2" inputs.

Net Income (Loss) Per Common Sh

Net Income (Loss) Per Common Share (Notes)	12 Months Ended
	Dec. 31, 2019
Net Income (Loss) Per Common Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Fiscal Year 2019 2018 2017 Weighted average number of common shares issued and outstanding 540.2 440.9 358.6 Weighted average number of fully vested restricted stock units outstanding 0.4 0.2 — Weighted average number of common shares outstanding - basic 540.6 441.1 358.6 Weighted average number of dilutive unvested restricted stock units outstanding 0.8 0.3 0.1 Weighted average number of common shares outstanding - diluted 541.4 441.4 358.7 Net income available to common stockholders $ 628 $ 93 $ 733 Net income per common share - basic $ 1.16 $ 0.21 $ 2.04 Net income per common share - diluted $ 1.16 $ 0.21 $ 2.04
Earnings Per Share [Text Block]	Net Income Per Common Share Basic net income per common share is computed by dividing (i) net income available 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 RSUs outstanding for the period granted under our long-term incentive program to employees and non-employee Board of Directors. Diluted net income 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): Fiscal Year 2019 2018 2017 Weighted average number of common shares issued and outstanding 540.2 440.9 358.6 Weighted average number of fully vested restricted stock units outstanding 0.4 0.2 — Weighted average number of common shares outstanding - basic 540.6 441.1 358.6 Weighted average number of dilutive unvested restricted stock units outstanding 0.8 0.3 0.1 Weighted average number of common shares outstanding - diluted 541.4 441.4 358.7 Net income available to common stockholders $ 628 $ 93 $ 733 Net income per common share - basic $ 1.16 $ 0.21 $ 2.04 Net income per common share - diluted $ 1.16 $ 0.21 $ 2.04

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Stockholders' Equity	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 December 31, 2019, 13,800 , 10,350 and 16,100 shares were designated as 7.00% Series C, 6.875% Series D and 6.50% Series E Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock, respectively, (referred to as Series C, D and E Preferred Stock, respectively). As of December 31, 2019, 13,000 , 9,400 and 16,100 shares of Series C, D and E Preferred Stock, respectively, were issued and outstanding, with an aggregate carrying value of $932 million and aggregate liquidation preference of $963 million . As of December 31, 2018, 8,050 and 13,800 shares of 7.750% Series B Cumulative Redeemable Preferred Stock ("Series B Preferred Stock") and Series C Preferred Stock, respectively, were designated and 7,000 and 13,000 shares, respectively, were issued and outstanding with an aggregate carrying value of $484 million and an aggregate liquidation preference of $500 million . Each share of Series B, C, D and E Preferred Stock represents 1,000 Series B, C, D and E Preferred Stock depositary shares, respectively. 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 such shares at $25.00 per depositary share, plus accumulated and unpaid dividends (whether or not declared), exclusively at our option. In November 2019, we redeemed all of the outstanding shares (and corresponding depositary shares) of our Series B Preferred Stock for $175 million (or $25.00 per depo sitary share), plus accrued and unpaid dividends to, but not including, the redemption date. In December, 2019, we filed a Certificate of Elimination of our Series B Preferred Stock with the Secretary of State of the State of Delaware, which eliminated the designation of Series B Preferred Stock from our amended and restated certificate of incorporation. Prior to the redemption date, holders of Series B Preferred Stock were entitled to receive cumulative cash dividends at a fixed rate of 7.750% per annum of their $25.00 per depositary share liquidation preference. In September 2017, we redeemed all of the outstanding shares of our 8.000% Series A Cumulative Redeemable Preferred Stock for their aggregate liquidation preference of $173 million , plus accrued and unpaid dividends, and, in October 2017, we eliminated the designation of Series A Preferred Stock from our amended and restated certificate of incorporation. Prior to the redemption date, holders of Series A Preferred Stock were entitled to receive cumulative cash dividends at a fixed rate of 8.000% per annum of their $25.00 per share liquidation preference. The following table includes a summary of preferred stock depositary shares issued and outstanding as of December 31, 2019 (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% Total 38.5 $ 932 $ 963 ________________________________ 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. Common Stock Offerings During fiscal year 2019, we did not complete a follow-on public offering of our common stock. During fiscal years 2018 and 2017, we completed follow-on public offerings of our common stock summarized in the table below (in millions, except for per share data). Follow-On Public Offering Price Received Per Share, Net Shares Net Proceeds Fiscal Year 2018: May 2018 $18.35 34.5 $ 633 August 2018 $18.68 43.7 817 November 2018 $17.09 46.0 786 Total fiscal year 2018 124.2 $ 2,236 Fiscal Year 2017: May 2017 $20.51 24.5 $ 503 September 2017 $20.47 28.2 577 Total fiscal year 2017 52.7 $ 1,080 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. The table below summarizes sales our common stock under the sales agreements during fiscal years 2019, 2018 and 2017 (in millions, except for per share data). As of December 31, 2019 , shares of our common stock with an aggregate offering price of $466 million remained authorized for issuance under this program through June 14, 2021. ATM Offerings Average Price Received Per Share, Net Shares Net Proceeds Fiscal Year 2019 $16.67 11.4 $ 190 Fiscal Year 2018 $18.03 20.8 $ 375 Fiscal Year 2017 $20.96 7.6 $ 159 Common Stock Repurchase Program From time-to-time we are authorized by our Board of Directors to repurchase shares of our common stock under certain conditions. In July 2019, our Board of Directors authorized the repurchase of up to $1 billion of our outstanding shares of common stock through December 31, 2020. During fiscal year 2019, we repurchased 6.9 million shares, or $103 million , of our common stock for an average repurchase price of $14.90 per common share, inclusive of transaction costs. As of December 31, 2019 , we had $0.9 billion of common stock remaining available for repurchase. Distributions to Stockholders The following table summarizes cash dividends declared during fiscal years 2019, 2018 and 2017 (in millions, except per share amounts): Dividends Declared Dividends Declared Per Share 8.000 % Series A Cumulative Redeemable Preferred Stock Fiscal year 2017 $ 9 $ 1.333000 7.750% Series B Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2019 $ 12 $ 1.673785 Fiscal year 2018 $ 14 $ 1.937500 Fiscal year 2017 $ 14 $ 1.937500 7.00% Series C Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2019 $ 23 $ 1.750000 Fiscal year 2018 $ 23 $ 1.750000 Fiscal year 2017 $ 9 $ 0.695140 7.00% Series D Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2019 $ 14 $ 1.475263 7.00% Series E Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2019 $ 7 $ 0.460420 Common Stock Fiscal year 2019 $ 1,081 $ 2.000000 Fiscal year 2018 $ 964 $ 2.160000 Fiscal year 2017 $ 777 $ 2.160000 Accumulated Other Comprehensive Income (Loss) The following table summarizes changes to accumulated OCI for fiscal years 2019, 2018 and 2017 (in millions): Fiscal Year Accumulated Other Comprehensive Income (Loss) 2019 2018 2017 Beginning Balance $ (943 ) $ (345 ) $ (397 ) OCI before reclassifications 1,031 (677 ) (31 ) Net loss amounts for available-for-sale securities reclassified from accumulated OCI to realized gain (loss) on sale of investment securities, net 9 79 83 Ending Balance $ 97 $ (943 ) $ (345 )

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Narrative [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes As of December 31, 2019, we have distributed all of our estimated taxable income for fiscal year 2019. Accordingly, we do not expect to incur an income tax liability on our 2019 taxable income. For fiscal years 2018 and 2017, we distributed all of our taxable income within the time limits prescribed by the Internal Revenue Code. Accordingly, we did not incur an income tax liability on our taxable income for such periods. Based on our analysis of any potential uncertain income tax positions, we concluded that we do not have any uncertain tax positions that meet the recognition or measurement criteria of ASC 740 as of December 31, 2019 or prior periods. Our tax returns for tax years 2016 and forward are open to examination by the IRS. If we incur income tax related interest and penalties, our policy is to classify them as a component of provision for income taxes.

Quarterly Results Quarterly Res

Quarterly Results Quarterly Results (Notes)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results	Quarterly Results (Unaudited) The following is a presentation of the quarterly results of operations and comprehensive income (loss) for fiscal years 2019 and 2018 (in millions, except per share data). Quarter Ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 Interest income: Interest income $ 705 $ 693 $ 676 $ 768 Interest expense 541 570 557 481 Net interest income 164 123 119 287 Other gain (loss): Gain on sale of investment securities, net 60 132 89 107 Unrealized gain (loss) on investment securities measured at fair value through net income, net 1,060 759 355 (160 ) Gain (loss) on derivative instruments and other securities, net (1,000 ) (1,438 ) (548 ) 662 Total other gain (loss), net 120 (547 ) (104 ) 609 Expenses: Compensation and benefits 10 11 10 16 Other operating expenses 9 9 9 9 Total expenses 19 20 19 25 Net income (loss) 265 (444 ) (4 ) 871 Dividends on preferred stock 10 13 13 18 Issuance cost of redeemed preferred stock — — — 6 Net income (loss) available (attributable) to common shareholders $ 255 $ (457 ) $ (17 ) $ 847 Net income (loss) $ 265 $ (444 ) $ (4 ) $ 871 Unrealized gain on investment securities measured at fair value through other comprehensive income (loss), net 400 379 246 15 Comprehensive income (loss) 665 (65 ) 242 886 Dividends on preferred stock 10 13 13 18 Issuance cost of redeemed preferred stock — — — 6 Comprehensive income (loss) available (attributable) to common shareholders $ 655 $ (78 ) $ 229 $ 862 Weighted average number of common shares outstanding - basic 536.7 537.8 546.4 541.4 Weighted average number of common shares outstanding - diluted 537.2 537.8 546.4 542.6 Net income (loss) per common share - basic $ 0.48 $ (0.85 ) $ (0.03 ) $ 1.56 Net income (loss) per common share - diluted $ 0.47 $ (0.85 ) $ (0.03 ) $ 1.56 Comprehensive income (loss) per common share - basic $ 1.22 $ (0.15 ) $ 0.42 $ 1.59 Comprehensive income (loss) per common share - diluted $ 1.22 $ (0.15 ) $ 0.42 $ 1.59 Dividends declared per common share $ 0.54 $ 0.50 $ 0.48 $ 0.48 Quarter Ended March 31, 2018 June 30, 2018 September 30, 2018 December 31, 2018 Interest income: Interest income $ 431 $ 414 $ 500 $ 604 Interest expense 206 237 312 418 Net interest income 225 177 188 186 Other gain (loss): Loss on sale of investment securities, net (2 ) (74 ) (40 ) (21 ) Unrealized gain (loss) on investment securities measured at fair value through net income, net (523 ) (94 ) (363 ) 683 Gain (loss) on derivative instruments and other securities, net 738 298 430 (1,633 ) Management fee income 4 4 46 — Total other gain (loss), net 217 134 73 (971 ) Expenses: Compensation and benefits 10 10 14 11 Other operating expenses 8 8 31 8 Total expenses 18 18 45 19 Net income (loss) 424 293 216 (804 ) Dividends on preferred stock 9 9 9 9 Net income (loss) available (attributable) to common shareholders $ 415 $ 284 $ 207 $ (813 ) Net income (loss) $ 424 $ 293 $ 216 $ (804 ) Unrealized gain (loss) on investment securities measured at fair value through other comprehensive income (loss), net (621 ) (145 ) (193 ) 361 Comprehensive income (loss) (197 ) 148 23 (443 ) Dividends on preferred stock 9 9 9 9 Comprehensive income (loss) available (attributable) to common shareholders $ (206 ) $ 139 $ 14 $ (452 ) Weighted average number of common shares outstanding - basic 391.3 404.9 462.3 504.2 Weighted average number of common shares outstanding - diluted 391.5 405.2 462.7 504.2 Net income (loss) per common share - basic and diluted $ 1.06 $ 0.70 $ 0.45 $ (1.61 ) Comprehensive income (loss) per common share - basic and diluted $ (0.53 ) $ 0.34 $ 0.03 $ (0.90 ) Dividends declared per common share $ 0.54 $ 0.54 $ 0.54 $ 0.54

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Event	Subsequent Events Preferred Stock Offering On February 11, 2020, we issued $575 million , or 23 million depositary shares, of 6.125% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock ("Series F Preferred Stock"), for net proceeds of $557 million . Each depositary share represents a 1/1,000th interest in a share of Series F Preferred Stock. At the conclusion of the Series F fixed rate period on April 15, 2025, the Series F Preferred Stock dividend will accrue at a floating rate equal to three-month LIBOR plus a spread of 4.697% per annum, and commencing on such date, the Series F Preferred Stock is redeemable at our option at the liquidation preference of $25.00 per depositary share, plus any accrued and unpaid dividends. Common Stock Dividend Declaration On January 9, 2020 and February 13, 2020 , our Board of Directors declared a monthly dividend of $0.16 per common share payable on February 11, 2020 and March 10, 2020 , respectively, to common stockholders of record as of January 31, 2020 and February 28, 2020

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
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. The fair value of our reverse repurchase agreements is assumed to equal cost as the interest rates are considered to be at market.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements We consider the applicability and impact of all Accounting Standards Updates ("ASUs") issued by the Financial Accounting Standards Board. ASUs not listed below were determined to be either not applicable, are not expected to have a significant impact on our consolidated financial statements when adopted or did not have a significant impact on our consolidated financial statements upon adoption. ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. Under ASU 2016-13, credit losses on available-for-sale investment securities are recorded as an allowance rather than as a direct reduction of amortized cost. Remaining losses unrelated to credit loss, such as due to changing interest rates, continue to be recorded through OCI. The new model also requires the estimation of lifetime expected credit losses and corresponding recognition of allowance for losses on trade and other receivables, held-to-maturity debt securities, loans, and other instruments held at amortized cost. The ASU requires certain recurring disclosures and is effective for annual periods, and interim periods within those annual periods, beginning on or after December 15, 2019. ASU 2016-13 is not expected to have a significant impact on our consolidated financial statements.
Variable Interest Entity Disclosure [Text Block]	Consolidated Variable Interest Entities ASC Topic 810, Consolidation ("ASC 810"), requires an enterprise to consolidate a variable interest entity ("VIE") if it is deemed the primary beneficiary of the VIE. As of December 31, 2019 and 2018 , our consolidated financial statements reflect the consolidation of certain VIEs for which we have determined we are the primary beneficiary. The consolidated VIEs consist of CMO trusts backed by fixed or adjustable-rate Agency RMBS. Fannie Mae or Freddie Mac guarantees the payment of interest and principal and acts as the trustee and administrator of their respective securitization trusts. Accordingly, we are not required to provide the beneficial interest holders of the CMO securities any financial or other support. Our maximum exposure to loss related to our involvement with the CMO trusts is the fair value of the CMO securities and interest and principal-only securities held by us, less principal amounts guaranteed by Fannie Mae and Freddie Mac. We elected the option to account for the debt of consolidated VIEs at fair value, with changes in fair value reflected in earnings during the period in which they occur. We believe this election more appropriately reflects our financial position as both the consolidated assets and consolidated debt are presented in a consistent manner on our consolidated balance sheets. We estimate the fair value of the consolidated debt based on the fair value of the Agency RMBS held by the CMO trusts, less the fair value of our retained interests in the trusts, which are measured on a market approach using "Level 2" inputs from third-party pricing services and dealer quotes, because such inputs are more observable than inputs to otherwise independently determine the value of our consolidated debt.
Share-based Payment Arrangement [Policy Text Block]	Stock-Based Compensation Under our 2016 AGNC Investment Corp. Equity and Incentive Compensation Plan (the "2016 Equity Plan" or "the Plan"), we may grant equity-based compensation to our officers and other employees and non-employee directors for the purpose of providing incentives and rewards for service or performance. Stock-based awards issued under the Plan include time-based and performance-based restricted stock unit awards ("RSU" and "PSU" awards, respectively), but may include other forms of equity-based compensation. RSU and PSU awards are an agreement to issue an equivalent number of shares of our common stock, plus any equivalent shares for dividends declared on our common stock, at the time the award vests, or later if distribution of such shares has been deferred beyond the vesting date. RSU awards vest over a specified service period. PSU awards vest over a specified service period subject to achieving long-term performance criteria. We measure and recognize compensation expense for all stock-based payment awards made to employees and non-employee directors based on their fair values. We value RSU and PSU awards based on the fair value of our common stock on the date of grant. Compensation expense is recognized over each award’s respective service period. In the case of PSU awards, we estimate the probability that the performance criteria will be achieved and recognize expense only for those awards expected to vest. We reevaluate our estimates each reporting period and recognize a cumulative effect adjustment to expense if our estimates change from the prior period. We do not estimate forfeiture rates; rather, we adjust for forfeitures in the periods in which they occur. Shares underlying RSU and PSU awards are issued on the vesting dates, or later if distribution of such shares has been deferred beyond the vesting date, net of shares withheld for minimum statutory tax withholdings to be paid by us on behalf of our employees. As a result, the actual number of shares issued will be fewer than the actual number of awards outstanding. When shares are withheld for statutory tax withholdings, we record a liability for tax withholding amounts to be paid by us as a reduction to additional paid-in capital.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents Cash and cash equivalents include cash held in bank accounts and cash held in money market funds on an overnight basis.
Goodwill Disclosure [Text Block]	Goodwill Goodwill is the cost of an acquisition in excess of the fair value of identified assets acquired and liabilities assumed and is recognized as an asset on our consolidated balance sheets. As of December 31, 2019 and 2018, we had $526 million of goodwill related to our acquisition of AGNC Management, LLC, our former manager, on July 1, 2016. Goodwill is not subject to amortization but must be tested for impairment at least annually and at interim periods when events or circumstances may make it more likely than not that an impairment has occurred. If a qualitative analysis indicates that there may be an impairment, a quantitative analysis is performed. The quantitative analysis requires that we compare the carrying value of the identified reporting unit comprising the goodwill to the reporting unit's fair value. If the reporting units' carrying value is greater than its fair value, an impairment charge is recognized to the extent the carrying amount of the reporting unit exceeds its fair value. During fiscal years 2019, 2018, and 2017, we did not recognize a goodwill impairment charge.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash Restricted cash includes cash pledged as collateral for clearing and executing trades, repurchase agreements and other borrowings, and interest rate swaps and other derivative instruments.
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 gains or losses 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, as the fair value changes for these assets are presented in a manner consistent with the presentation and timing of the fair value changes of our derivative instruments. We estimate the fair value of our investment securities based on prices provided by multiple third-party pricing services and non-binding dealer quotes (collectively "pricing sources"). These pricing sources use various valuation approaches, including market and income approaches, using "Level 2" inputs. The pricing sources primarily utilize a matrix pricing technique that interpolates the estimated fair value of our Agency RMBS 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, which may include maximum loan balance, loan vintage, loan-to-value ratio, geography and other characteristics as may be appropriate. The pricing sources may also utilize discounted cash flow model-derived pricing techniques to estimate the fair value of investment securities. 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 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. We review the pricing estimates obtained from the pricing sources and perform procedures to validate their reasonableness. Refer to Note 7 for further discussion of fair value measurements. We evaluate our investments designated as available-for-sale, on a quarterly basis, to assess whether a decline in the fair value of the security below its amortized cost basis is an other-than-temporary impairment ("OTTI"). The determination of whether a security is other-than-temporarily impaired may involve judgments and assumptions based on subjective and objective factors. When a security is impaired, an OTTI is considered to have occurred if any one of the following three conditions exists as of the financial reporting date: (i) we intend to sell the security (that is, a decision has been made to sell the security), (ii) it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis or (iii) we do not expect to recover the security's amortized cost basis, even if we do not intend to sell the security and it is not more likely than not that we will be required to sell the security. A general allowance for unidentified impairments in a portfolio of securities is not permitted. If either of the first two conditions exists as of the financial reporting date, the entire amount of the impairment loss, if any, is recognized in earnings as a realized loss and the cost basis of the security is adjusted to its fair value. If the third condition exists, the OTTI is separated into (i) the amount relating to credit loss (the "credit component") and (ii) the amount relating to all other factors (the "non-credit components"). Only the credit component is recognized in earnings, with the non-credit components recognized in OCI. We did not recognize OTTI charges on our investment securities for fiscal years 2019, 2018 or 2017.
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, 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 and compare the results to market consensus prepayment speeds, if available. We also consider historical prepayment speeds and current market conditions to validate the reasonableness of the third-party estimates. 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 transactions under master repurchase agreements. Pursuant to ASC Topic 860, Transfers and Servicing , we account for repurchase transactions 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. Interest rates on our repurchase agreements generally correspond to short-term benchmark rates plus or minus a fixed spread. The fair value of our repurchase agreements is assumed to equal cost as the interest rates are considered to be at market.
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. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized if the counterparties to these instruments fail to perform their obligations under the contracts. Our derivative agreements require that we post or receive collateral to mitigate such risk. We also attempt to minimize our risk of loss by limiting our counterparties to registered central clearing exchanges and major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. 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 three-month London Interbank Offered Rate ("LIBOR"), Overnight Index Swap Rate ("OIS") or Secured Overnight Financing Rate ("SOFR"). Our interest rate swaps typically have terms from one to 10 years but may extend up to 20 years or more. The majority of our interest rate swaps are centrally cleared through a registered commodities exchange. We value centrally cleared interest rate swaps 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. Our centrally cleared swaps require that we post an "initial margin" amount determined by the clearing 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. We value non-centrally cleared swaps using a combination of third-party valuations obtained from pricing services and the swap counterparty. The third-party valuations are model-driven using observable inputs, including short-term benchmark rates, swap rates and the forward yield curve. We also consider both our own and our counterparties' nonperformance risk in estimating the fair value of our interest rate swaps. In considering the effect of nonperformance risk, we assess the impact of netting and credit enhancements, such as collateral postings and guarantees, and have concluded that our own and our counterparty risk is not significant to the overall valuation of these agreements. 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. We estimate the fair value of interest rate swaptions using a combination of inputs from counterparty and third-party pricing models based on the fair 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, adjusted for non-performance risk, if any. 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. We estimate the fair value of TBA securities based on similar methods used to value our Agency RMBS securities. 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.
Income Tax Disclosure [Text Block]	Income Taxes As of December 31, 2019, we have distributed all of our estimated taxable income for fiscal year 2019. Accordingly, we do not expect to incur an income tax liability on our 2019 taxable income. For fiscal years 2018 and 2017, we distributed all of our taxable income within the time limits prescribed by the Internal Revenue Code. Accordingly, we did not incur an income tax liability on our taxable income for such periods. Based on our analysis of any potential uncertain income tax positions, we concluded that we do not have any uncertain tax positions that meet the recognition or measurement criteria of ASC 740 as of December 31, 2019 or prior periods. Our tax returns for tax years 2016 and forward are open to examination by the IRS. If we incur income tax related interest and penalties, our policy is to classify them as a component of provision for income taxes.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Share-based Payment Arrangement [Policy Text Block]	Stock-Based Compensation Under our 2016 AGNC Investment Corp. Equity and Incentive Compensation Plan (the "2016 Equity Plan" or "the Plan"), we may grant equity-based compensation to our officers and other employees and non-employee directors for the purpose of providing incentives and rewards for service or performance. Stock-based awards issued under the Plan include time-based and performance-based restricted stock unit awards ("RSU" and "PSU" awards, respectively), but may include other forms of equity-based compensation. RSU and PSU awards are an agreement to issue an equivalent number of shares of our common stock, plus any equivalent shares for dividends declared on our common stock, at the time the award vests, or later if distribution of such shares has been deferred beyond the vesting date. RSU awards vest over a specified service period. PSU awards vest over a specified service period subject to achieving long-term performance criteria. We measure and recognize compensation expense for all stock-based payment awards made to employees and non-employee directors based on their fair values. We value RSU and PSU awards based on the fair value of our common stock on the date of grant. Compensation expense is recognized over each award’s respective service period. In the case of PSU awards, we estimate the probability that the performance criteria will be achieved and recognize expense only for those awards expected to vest. We reevaluate our estimates each reporting period and recognize a cumulative effect adjustment to expense if our estimates change from the prior period. We do not estimate forfeiture rates; rather, we adjust for forfeitures in the periods in which they occur. Shares underlying RSU and PSU awards are issued on the vesting dates, or later if distribution of such shares has been deferred beyond the vesting date, net of shares withheld for minimum statutory tax withholdings to be paid by us on behalf of our employees. As a result, the actual number of shares issued will be fewer than the actual number of awards outstanding. When shares are withheld for statutory tax withholdings, we record a liability for tax withholding amounts to be paid by us as a reduction to additional paid-in capital.
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. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized if the counterparties to these instruments fail to perform their obligations under the contracts. Our derivative agreements require that we post or receive collateral to mitigate such risk. We also attempt to minimize our risk of loss by limiting our counterparties to registered central clearing exchanges and major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. 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 three-month London Interbank Offered Rate ("LIBOR"), Overnight Index Swap Rate ("OIS") or Secured Overnight Financing Rate ("SOFR"). Our interest rate swaps typically have terms from one to 10 years but may extend up to 20 years or more. The majority of our interest rate swaps are centrally cleared through a registered commodities exchange. We value centrally cleared interest rate swaps 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. Our centrally cleared swaps require that we post an "initial margin" amount determined by the clearing 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. We value non-centrally cleared swaps using a combination of third-party valuations obtained from pricing services and the swap counterparty. The third-party valuations are model-driven using observable inputs, including short-term benchmark rates, swap rates and the forward yield curve. We also consider both our own and our counterparties' nonperformance risk in estimating the fair value of our interest rate swaps. In considering the effect of nonperformance risk, we assess the impact of netting and credit enhancements, such as collateral postings and guarantees, and have concluded that our own and our counterparty risk is not significant to the overall valuation of these agreements. 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. We estimate the fair value of interest rate swaptions using a combination of inputs from counterparty and third-party pricing models based on the fair 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, adjusted for non-performance risk, if any. 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. We estimate the fair value of TBA securities based on similar methods used to value our Agency RMBS securities. 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 gains or losses 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, as the fair value changes for these assets are presented in a manner consistent with the presentation and timing of the fair value changes of our derivative instruments. We estimate the fair value of our investment securities based on prices provided by multiple third-party pricing services and non-binding dealer quotes (collectively "pricing sources"). These pricing sources use various valuation approaches, including market and income approaches, using "Level 2" inputs. The pricing sources primarily utilize a matrix pricing technique that interpolates the estimated fair value of our Agency RMBS 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, which may include maximum loan balance, loan vintage, loan-to-value ratio, geography and other characteristics as may be appropriate. The pricing sources may also utilize discounted cash flow model-derived pricing techniques to estimate the fair value of investment securities. 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 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. We review the pricing estimates obtained from the pricing sources and perform procedures to validate their reasonableness. Refer to Note 7 for further discussion of fair value measurements. We evaluate our investments designated as available-for-sale, on a quarterly basis, to assess whether a decline in the fair value of the security below its amortized cost basis is an other-than-temporary impairment ("OTTI"). The determination of whether a security is other-than-temporarily impaired may involve judgments and assumptions based on subjective and objective factors. When a security is impaired, an OTTI is considered to have occurred if any one of the following three conditions exists as of the financial reporting date: (i) we intend to sell the security (that is, a decision has been made to sell the security), (ii) it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis or (iii) we do not expect to recover the security's amortized cost basis, even if we do not intend to sell the security and it is not more likely than not that we will be required to sell the security. A general allowance for unidentified impairments in a portfolio of securities is not permitted. If either of the first two conditions exists as of the financial reporting date, the entire amount of the impairment loss, if any, is recognized in earnings as a realized loss and the cost basis of the security is adjusted to its fair value. If the third condition exists, the OTTI is separated into (i) the amount relating to credit loss (the "credit component") and (ii) the amount relating to all other factors (the "non-credit components"). Only the credit component is recognized in earnings, with the non-credit components recognized in OCI. We did not recognize OTTI charges on our investment securities for fiscal years 2019, 2018 or 2017.
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, 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 and compare the results to market consensus prepayment speeds, if available. We also consider historical prepayment speeds and current market conditions to validate the reasonableness of the third-party estimates. 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.

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Securities by Credit Rating [Table Text Block]	As of December 31, 2019 and 2018 , our investments in CRT and non-Agency securities had the following credit ratings: December 31, 2019 December 31, 2018 CRT and Non-Agency Security Credit Ratings 1 CRT RMBS CMBS CRT RMBS CMBS AAA $ — $ — $ 43 $ — $ 160 $ 52 AA — 81 214 — 17 152 A 13 25 34 17 33 15 BBB 67 71 69 25 43 53 BB 471 21 10 492 8 10 B 308 4 — 453 2 — Not Rated 117 7 — 25 3 — Total $ 976 $ 209 $ 370 $ 1,012 $ 266 $ 282 ________________________________ 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.
Available-for-sale Securities [Table Text Block]	December 31, 2018 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 17,591 $ 5,673 $ 25 $ 6 $ — $ — $ 23,295 Unamortized discount (10 ) (2 ) — — — — (12 ) Unamortized premium 912 343 — — — — 1,255 Amortized cost 18,493 6,014 25 6 — — 24,538 Gross unrealized gains 4 2 1 — — — 7 Gross unrealized losses (686 ) (264 ) — — — — (950 ) Total available-for-sale securities, at fair value 17,811 5,752 26 6 — — 23,595 Securities remeasured at fair value through earnings: Par value 39,453 18,428 — 268 281 968 59,398 Unamortized discount (78 ) (9 ) — (10 ) (6 ) — (103 ) Unamortized premium 1,055 638 — — 5 38 1,736 Amortized cost 40,430 19,057 — 258 280 1,006 61,031 Gross unrealized gains 223 57 — 2 3 18 303 Gross unrealized losses (386 ) (243 ) — — (1 ) (12 ) (642 ) Total securities remeasured at fair value through earnings 40,267 18,871 — 260 282 1,012 60,692 Total securities, at fair value $ 58,078 $ 24,623 $ 26 $ 266 $ 282 $ 1,012 $ 84,287 Weighted average coupon as of December 31, 2018 3.82 % 3.87 % 3.37 % 3.83 % 4.58 % 5.86 % 3.86 % Weighted average yield as of December 31, 2018 1 3.28 % 3.28 % 2.04 % 4.22 % 4.68 % 5.16 % 3.31 % ________________________________ 1. Incorporates a weighted average future constant prepayment rate assumption of 7.9% based on forward rates as of December 31, 2018 . December 31, 2019 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 14,301 $ 4,762 $ 18 $ — $ — $ — $ 19,081 Unamortized discount (10 ) (2 ) — — — — (12 ) Unamortized premium 711 276 — — — — 987 Amortized cost 15,002 5,036 18 — — — 20,056 Gross unrealized gains 142 29 1 — — — 172 Gross unrealized losses (50 ) (25 ) — — — — (75 ) Total available-for-sale securities, at fair value 15,094 5,040 19 — — — 20,153 Securities remeasured at fair value through earnings: Par value 45,106 29,881 — 208 348 937 76,480 Unamortized discount (68 ) (2 ) — (10 ) (3 ) (2 ) (85 ) Unamortized premium 1,218 967 — 1 7 26 2,219 Amortized cost 46,256 30,846 — 199 352 961 78,614 Gross unrealized gains 991 691 — 10 19 18 1,729 Gross unrealized losses (32 ) (18 ) — — (1 ) (3 ) (54 ) Total securities remeasured at fair value through earnings 47,215 31,519 — 209 370 976 80,289 Total securities, at fair value $ 62,309 $ 36,559 $ 19 $ 209 $ 370 $ 976 $ 100,442 Weighted average coupon as of December 31, 2019 3.62 % 3.75 % 3.77 % 4.05 % 4.49 % 5.07 % 3.68 % Weighted average yield as of December 31, 2019 1 3.03 % 3.09 % 2.08 % 4.39 % 4.38 % 4.05 % 3.07 % ________________________________ 1. Incorporates a weighted average future constant prepayment rate assumption of 10.8% based on forward rates as of December 31, 2019 .
Components of Investment Securities	The following tables summarize our investment securities as of December 31, 2019 and 2018 , excluding TBA securities, (dollars in millions). Details of our TBA securities as of each of the respective dates are included in Note 5 . December 31, 2019 December 31, 2018 Investment Securities Amortized Cost Fair Value Amortized Fair Value Agency RMBS: Fixed rate $ 96,375 $ 98,074 $ 83,047 $ 81,753 Adjustable rate 160 163 212 213 CMO 441 447 588 583 Interest-only and principal-only strips 146 164 172 178 Multifamily 37 39 — — Total Agency RMBS 97,159 98,887 84,019 82,727 Non-Agency RMBS 198 209 264 266 CMBS 352 370 280 282 CRT securities 961 976 1,006 1,012 Total investment securities $ 98,670 $ 100,442 $ 85,569 $ 84,287 December 31, 2019 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 14,301 $ 4,762 $ 18 $ — $ — $ — $ 19,081 Unamortized discount (10 ) (2 ) — — — — (12 ) Unamortized premium 711 276 — — — — 987 Amortized cost 15,002 5,036 18 — — — 20,056 Gross unrealized gains 142 29 1 — — — 172 Gross unrealized losses (50 ) (25 ) — — — — (75 ) Total available-for-sale securities, at fair value 15,094 5,040 19 — — — 20,153 Securities remeasured at fair value through earnings: Par value 45,106 29,881 — 208 348 937 76,480 Unamortized discount (68 ) (2 ) — (10 ) (3 ) (2 ) (85 ) Unamortized premium 1,218 967 — 1 7 26 2,219 Amortized cost 46,256 30,846 — 199 352 961 78,614 Gross unrealized gains 991 691 — 10 19 18 1,729 Gross unrealized losses (32 ) (18 ) — — (1 ) (3 ) (54 ) Total securities remeasured at fair value through earnings 47,215 31,519 — 209 370 976 80,289 Total securities, at fair value $ 62,309 $ 36,559 $ 19 $ 209 $ 370 $ 976 $ 100,442 Weighted average coupon as of December 31, 2019 3.62 % 3.75 % 3.77 % 4.05 % 4.49 % 5.07 % 3.68 % Weighted average yield as of December 31, 2019 1 3.03 % 3.09 % 2.08 % 4.39 % 4.38 % 4.05 % 3.07 %
Summary Of Agency Securities Estimated Weighted Average Life Classifications	The following table summarizes our investments as of December 31, 2019 and 2018 according to their estimated weighted average life classification (dollars in millions): December 31, 2019 December 31, 2018 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 $ 2,671 $ 2,654 3.54% 2.61% $ 1,690 $ 1,716 3.99% 2.64% > 3 years and ≤ 5 years 10,822 10,563 3.85% 3.20% 5,518 5,586 3.35% 2.73% > 5 years and ≤10 years 86,492 85,002 3.67% 3.07% 72,503 73,588 3.92% 3.37% > 10 years 457 451 3.31% 3.06% 4,576 4,679 3.57% 3.30% Total $ 100,442 $ 98,670 3.68% 3.07% $ 84,287 $ 85,569 3.86% 3.31%
Summary of Continuous Unrealized Loss Position of Available for Sale Securities	The following table presents the gross unrealized loss and fair values of securities classified as available-for-sale by length of time that such securities have been in a continuous unrealized loss position as of December 31, 2019 and 2018 (in millions): Unrealized Loss Position For Less than 12 Months 12 Months or More Total Securities Classified as Available-for-Sale Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss December 31, 2019 $ 1,653 $ (12 ) $ 6,984 $ (63 ) $ 8,637 $ (75 ) December 31, 2018 $ 4,783 $ (72 ) $ 18,231 $ (878 ) $ 23,014 $ (950 )
Summary of Net Gain from Sale of Agency Securities	The following table is a summary of our net gain (loss) from the sale of investment securities for fiscal years 2019, 2018 and 2017 by investment classification of accounting (in millions): Fiscal Year 2019 Fiscal Year 2018 Fiscal Year 2017 Investment Securities Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale 2 Fair Value Option Securities Total Investment securities sold, at cost $ (732 ) $ (23,040 ) $ (23,772 ) $ (4,306 ) $ (5,344 ) $ (9,650 ) $ (6,324 ) $ (12,913 ) $ (19,237 ) Proceeds from investment securities sold 1 723 23,437 24,160 4,227 5,286 9,513 6,241 12,933 19,174 Net gain (loss) on sale of investment securities $ (9 ) $ 397 $ 388 $ (79 ) $ (58 ) $ (137 ) $ (83 ) $ 20 $ (63 ) Gross gain on sale of investment securities $ — $ 401 $ 401 $ 6 $ 16 $ 22 $ 16 $ 48 $ 64 Gross loss on sale of investment securities (9 ) (4 ) (13 ) (85 ) (74 ) (159 ) (99 ) (28 ) (127 ) Net gain (loss) on sale of investment securities $ (9 ) $ 397 $ 388 $ (79 ) $ (58 ) $ (137 ) $ (83 ) $ 20 $ (63 ) ________________________________ 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.

Repurchase Agreements and Rev_2

Repurchase Agreements and Reverse Repurchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of Repurchase Agreements [Abstract]
Schedule of Borrowings under Repurchase Agreements and Weighted Average Interest Rates	he following table summarizes our borrowings under repurchase agreements by their remaining maturities as of December 31, 2019 and 2018 (dollars in millions): December 31, 2019 December 31, 2018 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 $ 56,664 2.19 % 10 $ 48,533 2.88 % 9 > 1 to ≤ 3 months 20,761 2.01 % 53 20,991 2.57 % 56 > 3 to ≤ 6 months 5,683 2.19 % 100 2,218 2.65 % 167 > 6 to ≤ 9 months 1,500 2.66 % 182 200 3.19 % 208 > 9 to ≤ 12 months 2,152 2.41 % 351 950 2.80 % 279 > 12 to ≤ 24 months 625 2.38 % 411 2,200 2.91 % 438 > 24 to ≤ 36 months 1,700 2.45 % 833 625 3.11 % 776 Total Agency repo 89,085 2.17 % 55 75,717 2.79 % 49 U.S. Treasury repo: > 1 day to ≤ 1 month 97 1.63 % 2 — — % — Total $ 89,182 2.17 % 55 $ 75,717 2.79 % 49

Derivative and Other Hedging _2

Derivative and Other Hedging Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
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) December 31, 2019 December 31, 2018 OIS 86 % — % 3M LIBOR 11 % 100 % SOFR 3 % — % 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 December 31, 2019 and 2018 (in millions): December 31, Derivative and Other Hedging Instruments Balance Sheet Location 2019 2018 Interest rate swaps Derivative assets, at fair value $ 21 $ 126 Swaptions Derivative assets, at fair value 126 37 TBA securities Derivative assets, at fair value 29 110 U.S. Treasury futures - short Derivative assets, at fair value 14 — Total derivative assets, at fair value $ 190 $ 273 Interest rate swaps Derivative liabilities, at fair value $ (2 ) $ — TBA securities Derivative liabilities, at fair value (4 ) (40 ) U.S. Treasury futures - short Derivative liabilities, at fair value — (44 ) Total derivative liabilities, at fair value $ (6 ) $ (84 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ 97 $ 46 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (9,543 ) (21,431 ) Total U.S. Treasury securities, net at fair value $ (9,446 ) $ (21,385 )
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 Average Receive Rate (LIBOR) Average Term (Years) December 31, 2019 ≤ 1 year $ 123 $ 80 8 $ 5,650 2.26% 3M 9.3 > 1 year ≤ 2 years 53 46 16 3,200 2.50% 3M 10.0 Total $ 176 $ 126 11 $ 8,850 2.34% 3M 9.5 December 31, 2018 ≤ 1 year $ 80 $ 23 4 $ 3,000 2.96% 3M 7.0 > 1 year ≤ 2 years 18 14 18 500 2.78% 3M 10.0 Total $ 98 $ 37 6 $ 3,500 2.93% 3M 7.4 ________________________________ 1. As of December 31, 2019 and 2018 , ≤ 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. U.S. Treasury Securities December 31, 2019 December 31, 2018 Maturity Face Amount Long/(Short) Cost Basis 1 Fair Value Face Amount Long/(Short) Cost Basis 1 Fair Value 5 years $ 95 $ 95 $ 97 $ (703 ) $ (706 ) $ (713 ) 7 years — — — (14,357 ) (14,325 ) (14,410 ) 10 years (9,224 ) (9,329 ) (9,543 ) (6,240 ) (6,224 ) (6,262 ) Total U.S. Treasury securities $ (9,129 ) $ (9,234 ) $ (9,446 ) $ (21,300 ) $ (21,255 ) $ (21,385 )
US government securities	U.S. Treasury Securities December 31, 2019 December 31, 2018 Maturity Face Amount Long/(Short) Cost Basis 1 Fair Value Face Amount Long/(Short) Cost Basis 1 Fair Value 5 years $ 95 $ 95 $ 97 $ (703 ) $ (706 ) $ (713 ) 7 years — — — (14,357 ) (14,325 ) (14,410 ) 10 years (9,224 ) (9,329 ) (9,543 ) (6,240 ) (6,224 ) (6,262 ) Total U.S. Treasury securities $ (9,129 ) $ (9,234 ) $ (9,446 ) $ (21,300 ) $ (21,255 ) $ (21,385 ) ________________________________ 1. As of December 31, 2019 and 2018 , short U.S. Treasury securities had a weighted average yield of 2.19% and 2.66% , respectively, and long U.S. Treasury securities had a weighted average yield of 2.21% and 2.98% , respectively.
US Government Futures Securities [Table Text Block]	U.S. Treasury Futures December 31, 2019 December 31, 2018 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 $ (1,000 ) $ (1,298 ) $ (1,284 ) $ 14 $ (1,650 ) $ (1,969 ) $ (2,013 ) $ (44 ) ________________________________ 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.
Summary of Long and Short Position of Derivative Instruments	December 31, 2019 December 31, 2018 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: 2.5% $ 805 $ 811 $ 812 $ 1 $ — $ — $ — $ — 3.0% 1,059 1,083 1,086 3 567 557 566 9 3.5% 241 250 250 — 1,706 1,708 1,726 18 4.0% 75 78 78 — 1,350 1,370 1,381 11 Total 15-Year TBA securities 2,180 2,222 2,226 4 3,623 3,635 3,673 38 30-Year TBA securities: ≤3.0% 5,008 5,052 5,073 21 1,028 981 1,003 22 3.5% 1,226 1,259 1,261 2 (2,979 ) (2,943 ) (2,977 ) (34 ) 4.0% (1,507 ) (1,565 ) (1,568 ) (3 ) 3,030 3,073 3,089 16 ≥ 4.5% 415 436 437 1 2,450 2,506 2,534 28 Total 30-Year TBA securities, net 5,142 5,182 5,203 21 3,529 3,617 3,649 32 Total TBA securities, net $ 7,322 $ 7,404 $ 7,429 $ 25 $ 7,152 $ 7,252 $ 7,322 $ 70 ________________________________ 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.
Schedule Of Outstanding Not Designated As Hedging Instruments	The following table summarizes changes in our derivative and other hedge portfolio and their effect on our consolidated statements of comprehensive income for fiscal years 2019, 2018 and 2017 (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 Fiscal Year 2019: TBA securities, net $ 7,152 95,169 (94,999 ) $ 7,322 $ 411 Interest rate swaps - payer $ 51,625 166,975 (139,525 ) $ 79,075 (1,645 ) Interest rate swaps - receiver $ — (175 ) 175 $ — — Payer swaptions $ 3,500 7,650 (2,300 ) $ 8,850 (26 ) U.S. Treasury securities - short position $ (21,345 ) (12,601 ) 24,722 $ (9,224 ) (967 ) U.S. Treasury securities - long position $ 45 1,776 (1,726 ) $ 95 11 U.S. Treasury futures contracts - short position $ (1,650 ) (5,300 ) 5,950 $ (1,000 ) (109 ) $ (2,325 ) Fiscal Year 2018: TBA securities, net $ 15,474 194,534 (202,856 ) $ 7,152 $ (299 ) Interest rate swaps $ 43,700 14,350 (6,425 ) $ 51,625 140 Payer swaptions $ 6,650 1,250 (4,400 ) $ 3,500 90 U.S. Treasury securities - short position $ (10,699 ) (19,278 ) 8,632 $ (21,345 ) (161 ) U.S. Treasury securities - long position $ — 1,949 (1,904 ) $ 45 1 U.S. Treasury futures contracts - short position $ (2,910 ) (7,859 ) 9,119 $ (1,650 ) 48 $ (181 ) Fiscal Year 2017: TBA securities, net $ 10,916 237,601 (233,043 ) $ 15,474 $ 330 Interest rate swaps $ 37,175 14,825 (8,300 ) $ 43,700 67 Payer swaptions $ 1,200 6,450 (1,000 ) $ 6,650 (66 ) U.S. Treasury securities - short position $ (8,061 ) (14,030 ) 11,392 $ (10,699 ) (141 ) U.S. Treasury securities - long position $ 189 404 (593 ) $ — 1 U.S. Treasury futures contracts - short position $ (1,810 ) (11,340 ) 10,240 $ (2,910 ) — $ 191 ________________________________ 1.
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 December 31, 2019 and 2018 (dollars in millions): December 31, 2019 December 31, 2018 Pay Fixed / Receive Variable Interest Rate Swaps Notional Average Rate Average Average Notional 1 Average Rate 2 Average Average ≤ 3 years $ 59,700 1.30% 1.58% 1.6 $ 19,900 1.63% 2.62% 1.3 > 3 to ≤ 5 years 9,850 1.17% 1.55% 3.8 8,425 2.06% 2.61% 4.0 > 5 to ≤ 7 years 5,650 1.34% 1.70% 6.4 7,875 2.66% 2.66% 6.1 > 7 to ≤ 10 years 2,850 1.36% 1.58% 8.9 10,550 2.36% 2.64% 8.8 > 10 years 1,025 1.64% 1.78% 15.4 4,875 2.77% 2.63% 11.6 Total $ 79,075 1.29% 1.59% 2.7 $ 51,625 2.11% 2.63% 5.0

Pledged Assets (Tables)

Pledged Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Pledged Assets [Abstract]
Schedule of Securities and Cash Pledged as Collateral from Counterparties [Table Text Block]	As of December 31, 2019 and 2018 , we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions). December 31, 2019 December 31, 2018 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 $ 10,099 $ — $ 1 $ 10,100 $ 21,876 $ 35 $ 37 $ 21,948 Cash — 116 — 116 — 129 — 129 Total $ 10,099 $ 116 $ 1 $ 10,216 $ 21,876 $ 164 $ 37 $ 22,077
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 December 31, 2019 and 2018 (in millions): December 31, 2019 Assets Pledged to Counterparties 1 Repurchase Agreements 2 Debt of Consolidated VIEs Derivative Agreements Brokerage and Clearing Agreements 3 Total Agency RMBS - fair value $ 92,142 $ 371 $ 404 $ 206 $ 93,123 CRT - fair value 309 — — — 309 U.S. Treasury securities - fair value 453 — — 28 481 Accrued interest on pledged securities 267 1 1 1 270 Restricted cash and cash equivalents 111 — 340 — 451 Total $ 93,282 $ 372 $ 745 $ 235 $ 94,634 December 31, 2018 Assets Pledged to Counterparties 1 Repurchase Agreements 2 Debt of Consolidated VIEs Derivative Agreements Brokerage and Clearing Agreements 3 Total Agency RMBS - fair value $ 78,997 $ 436 $ 174 $ 133 $ 79,740 CRT - fair value 141 — — — 141 Non-Agency - fair value 45 — — — 45 U.S. Treasury securities - fair value 437 — — — 437 Accrued interest on pledged securities 246 1 1 — 248 Restricted cash and cash equivalents 77 — 522 — 599 Total $ 79,943 $ 437 $ 697 $ 133 $ 81,210 ________________________________ 1. Includes repledged assets received as collateral from counterparties. 2. Includes $144 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of December 31, 2019 and 2018 , 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 December 31, 2019 and 2018 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 4 . December 31, 2019 December 31, 2018 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 $ 56,990 $ 55,951 $ 167 $ 49,944 $ 50,654 $ 156 > 30 and ≤ 60 days 14,410 14,114 42 14,586 14,810 46 > 60 and ≤ 90 days 7,637 7,536 20 7,770 7,843 24 > 90 days 13,510 13,286 38 6,882 7,079 21 Total $ 92,547 $ 90,887 $ 267 $ 79,182 $ 80,386 $ 247 ________________________________ 1. Includes $144 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of December 31, 2019 and 2018 , respectively. 2. Excludes $357 million
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 December 31, 2019 and 2018 (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 December 31, 2019 Interest rate swap and swaption agreements, at fair value 1 $ 147 $ — $ 147 $ (2 ) $ (116 ) $ 29 TBA securities, at fair value 29 — 29 (4 ) — 25 Receivable under reverse repurchase agreements 10,181 — 10,181 (9,852 ) (329 ) — Total $ 10,357 $ — $ 10,357 $ (9,858 ) $ (445 ) $ 54 December 31, 2018 Interest rate swap and swaption agreements, at fair value 1 $ 163 $ — $ 163 $ — $ (158 ) $ 5 TBA securities, at fair value 110 — 110 (40 ) — 70 Receivable under reverse repurchase agreements 21,813 — 21,813 (17,236 ) (4,575 ) 2 Total $ 22,086 $ — $ 22,086 $ (17,276 ) $ (4,733 ) $ 77
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 December 31, 2019 Interest rate swap agreements, at fair value 1 $ 2 $ — $ 2 $ (2 ) $ — $ — TBA securities, at fair value 4 — 4 (4 ) — — Repurchase agreements 89,182 — 89,182 (9,852 ) (79,330 ) — Total $ 89,188 $ — $ 89,188 $ (9,858 ) $ (79,330 ) $ — December 31, 2018 Interest rate swap agreements, at fair value 1 $ — $ — $ — $ — $ — $ — TBA securities, at fair value 40 — 40 (40 ) — — Repurchase agreements 75,717 — 75,717 (17,236 ) (58,481 ) — Total $ 75,757 $ — $ 75,757 $ (17,276 ) $ (58,481 ) $ — ________________________________ 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.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table provides a summary of our assets and liabilities that are measured at fair value on a recurring basis, as of December 31, 2019 and 2018 , based on their categorization within the valuation hierarchy (in millions). There were no transfers between valuation hierarchy levels during the periods presented. December 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 98,516 $ — $ — $ 82,291 $ — Agency securities transferred to consolidated VIEs — 371 — — 436 — Credit risk transfer securities — 976 — — 1,012 — Non-Agency securities — 579 — — 548 — U.S. Treasury securities 97 — — 46 — — Interest rate swaps — 21 — — 126 — Swaptions — 126 — — 37 — TBA securities — 29 — — 110 — U.S. Treasury futures 14 — — — — — Total $ 111 $ 100,618 $ — $ 46 $ 84,560 $ — Liabilities: Debt of consolidated VIEs $ — $ 228 $ — $ — $ 275 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 9,543 — — 21,431 — — Interest rate swaps — 2 — — — — TBA securities — 4 — — 40 — U.S. Treasury futures — — — 44 — — Total $ 9,543 $ 234 $ — $ 21,475 $ 315 $ —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2019
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% Total 38.5 $ 932 $ 963 ________________________________
Schedule of Stock by Class [Table Text Block]	ATM Offerings Average Price Received Per Share, Net Shares Net Proceeds Fiscal Year 2019 $16.67 11.4 $ 190 Fiscal Year 2018 $18.03 20.8 $ 375 Fiscal Year 2017 $20.96 7.6 $ 159 Follow-On Public Offering Price Received Per Share, Net Shares Net Proceeds Fiscal Year 2018: May 2018 $18.35 34.5 $ 633 August 2018 $18.68 43.7 817 November 2018 $17.09 46.0 786 Total fiscal year 2018 124.2 $ 2,236 Fiscal Year 2017: May 2017 $20.51 24.5 $ 503 September 2017 $20.47 28.2 577 Total fiscal year 2017 52.7 $ 1,080
Dividends Declared [Table Text Block]	Dividends Declared Dividends Declared Per Share 8.000 % Series A Cumulative Redeemable Preferred Stock Fiscal year 2017 $ 9 $ 1.333000 7.750% Series B Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2019 $ 12 $ 1.673785 Fiscal year 2018 $ 14 $ 1.937500 Fiscal year 2017 $ 14 $ 1.937500 7.00% Series C Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2019 $ 23 $ 1.750000 Fiscal year 2018 $ 23 $ 1.750000 Fiscal year 2017 $ 9 $ 0.695140 7.00% Series D Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2019 $ 14 $ 1.475263 7.00% Series E Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2019 $ 7 $ 0.460420 Common Stock Fiscal year 2019 $ 1,081 $ 2.000000 Fiscal year 2018 $ 964 $ 2.160000 Fiscal year 2017 $ 777 $ 2.160000
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes changes to accumulated OCI for fiscal years 2019, 2018 and 2017 (in millions): Fiscal Year Accumulated Other Comprehensive Income (Loss) 2019 2018 2017 Beginning Balance $ (943 ) $ (345 ) $ (397 ) OCI before reclassifications 1,031 (677 ) (31 ) Net loss amounts for available-for-sale securities reclassified from accumulated OCI to realized gain (loss) on sale of investment securities, net 9 79 83 Ending Balance $ 97 $ (943 ) $ (345 )

Organization (Details)

Organization (Details)	12 Months Ended
	Dec. 31, 2019
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%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2019
Derivative [Line Items]
Required Annual Distribution of Taxable Net Income	90.00%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies Goodwill and Intangible Assets (Details) $ in Millions	Dec. 31, 2019USD ($)
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 526

Summary of Significant Accoun_6

Summary of Significant Accounting Policies Variable Interest Entities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Other Long-term Debt	$ 228	$ 275

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	$ 100,400	$ 84,300
Weighted average expected constant prepayment rate	10.80%	7.90%
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ (371)	$ (436)
Debt, at fair value	(228)	(275)
Agency Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Unamortized premium balance	3,100	2,900
TBA securities Fifteen Year and Thirty Year Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Net long TBA position, at fair value	7,400	7,300
TBA, net carrying value	$ 25	$ 70

Investment Securities Investmen

Investment Securities Investment Securities (Summary of Investment in Agency Security) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	$ 98,670	$ 85,569
Debt Securities, Trading and Available-for-sale	100,442	84,287
Total agency MBS, at fair value	98,887	82,727
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	198	264
Debt Securities, Trading and Available-for-sale	209	266
Commercial Mortgage Backed Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	352	280
Debt Securities, Trading and Available-for-sale	370	282
Credit Risk Transfer Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	961	1,006
Debt Securities, Trading and Available-for-sale	976	1,012
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	96,375	83,047
Debt Securities, Trading and Available-for-sale	98,074	81,753
Adjustable-Rate [Member] | Agency Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	160	212
Debt Securities, Trading and Available-for-sale	163	213
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	441	588
Debt Securities, Trading and Available-for-sale	447	583
Multifamily [Member] | Agency Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	37	0
Debt Securities, Trading and Available-for-sale	39	0
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	146	172
Debt Securities, Trading and Available-for-sale	164	178
Agency Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	$ 97,159	$ 84,019

Investment Securities (Componen

Investment Securities (Components Of Investment Securities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Agency securities transferred to consolidated VIEs	$ 371	$ 436
Debt Securities, Trading	80,289	60,692
Debt Securities, Trading and Available-for-sale	100,442	84,287
Amortized cost	$ 98,670	$ 85,569
Weighted average coupon	3.68%	3.86%
Weighted average yield	3.07%	3.31%
Future Prepayment Rate Assumption Of Investment Portfolio	10.80%	7.90%
Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 19,081	$ 23,295
Unamortized discount	(12)	(12)
Unamortized premium	987	1,255
Amortized cost	20,056	24,538
Gross unrealized gains	172	7
Gross unrealized losses	(75)	(950)
Total available-for-sale securities, at fair value	20,153	23,595
Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(85)	(103)
Unamortized premium	2,219	1,736
Debt Securities, Trading, Unrealized Gain	1,729	303
Debt Securities, Trading, Unrealized Loss	(54)	(642)
Trading Securities, Cost	78,614	61,031
Trading Securities Par	76,480	59,398
Fannie Mae [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	47,215	40,267
Debt Securities, Trading and Available-for-sale	$ 62,309	$ 58,078
Weighted average coupon	3.62%	3.82%
Weighted average yield	3.03%	3.28%
Fannie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 14,301	$ 17,591
Unamortized discount	(10)	(10)
Unamortized premium	711	912
Amortized cost	15,002	18,493
Gross unrealized gains	142	4
Gross unrealized losses	(50)	(686)
Total available-for-sale securities, at fair value	15,094	17,811
Fannie Mae [Member] | Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(68)	(78)
Unamortized premium	1,218	1,055
Debt Securities, Trading, Unrealized Gain	991	223
Debt Securities, Trading, Unrealized Loss	(32)	(386)
Trading Securities, Cost	46,256	40,430
Trading Securities Par	45,106	39,453
Freddie Mac [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	31,519	18,871
Debt Securities, Trading and Available-for-sale	$ 36,559	$ 24,623
Weighted average coupon	3.75%	3.87%
Weighted average yield	3.09%	3.28%
Freddie Mac [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 4,762	$ 5,673
Unamortized discount	(2)	(2)
Unamortized premium	276	343
Amortized cost	5,036	6,014
Gross unrealized gains	29	2
Gross unrealized losses	(25)	(264)
Total available-for-sale securities, at fair value	5,040	5,752
Freddie Mac [Member] | Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(2)	(9)
Unamortized premium	967	638
Debt Securities, Trading, Unrealized Gain	691	57
Debt Securities, Trading, Unrealized Loss	(18)	(243)
Trading Securities, Cost	30,846	19,057
Trading Securities Par	29,881	18,428
Ginnie Mae [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	0	0
Debt Securities, Trading and Available-for-sale	$ 19	$ 26
Weighted average coupon	3.77%	3.37%
Weighted average yield	2.08%	2.04%
Ginnie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 18	$ 25
Unamortized discount	0	0
Unamortized premium	0	0
Amortized cost	18	25
Gross unrealized gains	1	1
Gross unrealized losses	0	0
Total available-for-sale securities, at fair value	19	26
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	0	0
Trading Securities Par	0	0
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	209	260
Debt Securities, Trading and Available-for-sale	$ 209	$ 266
Weighted average coupon	4.05%	3.83%
Weighted average yield	4.39%	4.22%
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 0	$ 6
Unamortized discount	0	0
Unamortized premium	0	0
Amortized cost	0	6
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Total available-for-sale securities, at fair value	0	6
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(10)	(10)
Unamortized premium	1	0
Debt Securities, Trading, Unrealized Gain	10	2
Debt Securities, Trading, Unrealized Loss	0	0
Trading Securities, Cost	199	258
Trading Securities Par	208	268
Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	370	282
Debt Securities, Trading and Available-for-sale	$ 370	$ 282
Weighted average coupon	4.49%	4.58%
Weighted average yield	4.38%	4.68%
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	(3)	(6)
Unamortized premium	7	5
Debt Securities, Trading, Unrealized Gain	19	3
Debt Securities, Trading, Unrealized Loss	(1)	(1)
Trading Securities, Cost	352	280
Trading Securities Par	348	281
Credit Risk Transfer Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	976	1,012
Debt Securities, Trading and Available-for-sale	$ 976	$ 1,012
Weighted average coupon	5.07%	5.86%
Weighted average yield	4.05%	5.16%
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	(2)	0
Unamortized premium	26	38
Debt Securities, Trading, Unrealized Gain	18	18
Debt Securities, Trading, Unrealized Loss	(3)	(12)
Trading Securities, Cost	961	1,006
Trading Securities Par	937	968
Credit Risk Transfer Securities [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading and Available-for-sale	$ 976	$ 1,012

Investment Securities (Summary

Investment Securities (Summary Of Agency Securities Estimated Weighted Average Life Classifications) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Agency securities classified as available for sale, Fair value	$ 100,442	$ 84,287
Agency securities classified as available for sale, Amortized cost	$ 98,670	$ 85,569
Weighted Average Coupon	3.68%	3.86%
Weighted Average Yield	3.07%	3.31%
Less Than or Equal to Three Years [Member]
Fair Value	$ 2,671	$ 1,690
Amortized Cost	$ 2,654	$ 1,716
Weighted Average Coupon	3.54%	3.99%
Weighted Average Yield	2.61%	2.64%
Greater Than Three Years and Less Than or Equal to Five Years [Member]
Fair Value	$ 10,822	$ 5,518
Amortized Cost	$ 10,563	$ 5,586
Weighted Average Coupon	3.85%	3.35%
Weighted Average Yield	3.20%	2.73%
Greater Than Five Years [Member]
Fair Value	$ 86,492	$ 72,503
Amortized Cost	$ 85,002	$ 73,588
Weighted Average Coupon	3.67%	3.92%
Weighted Average Yield	3.07%	3.37%
Greater Than Ten Years [Member]
Fair Value	$ 457	$ 4,576
Amortized Cost	$ 451	$ 4,679
Weighted Average Coupon	3.31%	3.57%
Weighted Average Yield	3.06%	3.30%

Investment Securities (Summar_2

Investment Securities (Summary Of Changes In Accumulated OCI For Available-For-Sale Security) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Unrealized Gains and (Losses), Net	$ 15	$ 246	$ 379	$ 400	$ 361	$ (193)	$ (145)	$ (621)	$ 1,040	$ (598)	$ 52
Agency Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning OCI Balance				$ (943)				$ (345)	(943)	(345)	(397)
Unrealized Gains and (Losses), Net									1,031	(677)	(31)
Reversal of Unrealized (Gains) and Losses, Net on Realization									9	79	83
Ending OCI Balance	$ 97				$ (943)				$ 97	$ (943)	$ (345)

Investment Securities (Summar_3

Investment Securities (Summary Of Continuous Unrealized Loss Positions Of Available-For-Sale Security) (Details) - Accumulated Other Comprehensive Income (Loss) [Member] - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Unrealized Loss Position For - Estimated Fair Value - Less than 12 Months	$ 1,653	$ 4,783
Unrealized Loss Position For - Unrealized Loss - Less than 12 Months	(12)	(72)
Unrealized Loss Position For - Estimated Fair Value - 12 Months or More	6,984	18,231
Unrealized Loss Position For - Unrealized Loss - 12 Months or More	(63)	(878)
Unrealized Loss Position For - Estimated Fair Value - Total	8,637	23,014
Unrealized Loss Position For - Unrealized Loss - Total	$ (75)	$ (950)

Investment Securities (Summar_4

Investment Securities (Summary Of Net Gain From Sale Of Agency Securities) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cost of Sale of Fair Value Option Securities									$ (23,040)	$ (5,344)	$ (12,913)
Cost of Sale of Investment Securities									(23,772)	(9,650)	(19,237)
Proceeds from agency MBS sold									13,555	21,308	14,557
Net gain (loss) on sale of investment securities	$ 107	$ 89	$ 132	$ 60	$ (21)	$ (40)	$ (74)	$ (2)	388	(137)	(63)
Available-for-sale Securities [Member]
Agency MBS sold, at cost									(732)	(4,306)	(6,324)
Proceeds from agency MBS sold									723	4,227	6,241
Net gain (loss) on sale of investment securities										(79)	(83)
Gross gain on sale of investment securities									0	6	16
Gross loss on sale of investment securities									(9)	(85)	(99)
Securities Remeasured at Fair Value [Member]
Proceeds from agency MBS sold									23,437	5,286	12,933
Net gain (loss) on sale of investment securities										(58)	20
Gross gain on sale of investment securities									401	16	48
Gross loss on sale of investment securities									(4)	(74)	(28)
Securities (Assets) [Member]
Proceeds from agency MBS sold									24,160	9,513	19,174
Net gain (loss) on sale of investment securities									388	(137)	(63)
Gross gain on sale of investment securities									401	22	64
Gross loss on sale of investment securities									(13)	$ (159)	$ (127)
Cost and Proceeds of Investment Securities [Member] | Available-for-sale Securities [Member]
Net gain (loss) on sale of investment securities									(9)
Cost and Proceeds of Investment Securities [Member] | Securities Remeasured at Fair Value [Member]
Net gain (loss) on sale of investment securities									397
Gross Gain & Loss of Investment Securities [Member] | Available-for-sale Securities [Member]
Net gain (loss) on sale of investment securities									(9)
Gross Gain & Loss of Investment Securities [Member] | Securities Remeasured at Fair Value [Member]
Net gain (loss) on sale of investment securities									$ 397

Investment Securities Securitie

Investment Securities Securities by Credit Rating (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	$ 80,289	$ 60,692
Debt Securities, Trading and Available-for-sale	100,442	84,287
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	209	260
Debt Securities, Trading and Available-for-sale	209	266
Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	370	282
Debt Securities, Trading and Available-for-sale	370	282
Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	976	1,012
Debt Securities, Trading and Available-for-sale	976	1,012
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	976	1,012
BBB Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	71	43
BBB Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	69	53
BBB Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	67	25
BB Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	21	8
BB Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	10	10
BB Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	471	492
AAA Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	160
AAA Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	43	52
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	81	17
AA Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	214	152
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	25	33
A Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	34	15
A Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	13	17
B Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	4	2
B Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
B Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	308	453
Not Rated [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	7	3
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	$ 117	$ 25

Repurchase Agreements And Rev_3

Repurchase Agreements And Reverse Repurchase Agreements (Narrative) (Details) $ in Millions	Dec. 31, 2019USD ($)days	Dec. 31, 2018USD ($)days
Assets Sold under Agreements to Repurchase [Line Items]
Receivable Under Reverse Repurchase Agreements	$ 10,181	$ 21,813
Securities Sold under Agreements to Repurchase	89,182	75,717
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 9,543	$ 21,431
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.17%	2.79%
Debt of consolidated variable interest entities, at fair value	$ (228)	$ (275)
TBA securities Fifteen Year and Thirty Year Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Fair Value, Net	25	70
TBA and Forward Settling Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Forward Settlement Value	7,404	7,252
Derivative, Fair Value, Net	25	70
Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	17,000	19,500
Forward Contracts [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	$ 4,500	$ 10,700
Weighted Average Forward Start Days | days	12	9
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.60%	2.90%
Bethesda Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Percentage of Repurchase Agreement Funding	40.00%	35.00%
FICC [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Percentage of Repurchase Agreement Funding	38.00%	33.00%
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 5,400	$ 4,500

Repurchase Agreements And Other

Repurchase Agreements And Other Debt (Repurchase Arrangements And Weighted Average Interest Rates Classified By Original Maturities) (Details) $ in Millions	Dec. 31, 2019USD ($)days	Dec. 31, 2018USD ($)days
Receivable Under Reverse Repurchase Agreements	$ 10,181	$ 21,813
Repurchase Agreements	$ 89,182	$ 75,717
Weighted Average Interest Rate	2.17%	2.79%
Weighted Average Days to Maturity | days	55	49
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 9,543	$ 21,431
Maturity Overnight [Member]
Repurchase Agreements	17,000	19,500
30 Days or Less [Member]
Repurchase Agreements	$ 56,664	$ 48,533
Weighted Average Interest Rate	2.19%	2.88%
Weighted Average Days to Maturity | days	10	9
1 to 3 Months
Repurchase Agreements	$ 20,761	$ 20,991
Weighted Average Interest Rate	2.01%	2.57%
Weighted Average Days to Maturity | days	53	56
3 to 6 Months
Repurchase Agreements	$ 5,683	$ 2,218
Weighted Average Interest Rate	2.19%	2.65%
Weighted Average Days to Maturity | days	100	167
6 to 9 Months
Repurchase Agreements	$ 1,500	$ 200
Weighted Average Interest Rate	2.66%	3.19%
Weighted Average Days to Maturity | days	182	208
9 to 12 Months
Repurchase Agreements	$ 2,152	$ 950
Weighted Average Interest Rate	2.41%	2.80%
Weighted Average Days to Maturity | days	351	279
12 to 24 Months
Repurchase Agreements	$ 625	$ 2,200
Weighted Average Interest Rate	2.38%	2.91%
Weighted Average Days to Maturity | days	411	438
24 to 36 Months
Repurchase Agreements	$ 1,700	$ 625
Weighted Average Interest Rate	2.45%	3.11%
Weighted Average Days to Maturity | days	833	776
US Treasury Securities [Member] | 2 Days to 1 Month [Member]
Repurchase Agreements	$ 97	$ 0
Weighted Average Interest Rate	1.63%	0.00%
Weighted Average Days to Maturity | days	2	0
FICC [Member]
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 5,400	$ 4,500
US Government Agencies Debt Securities [Member]
Repurchase Agreements	$ 89,085	$ 75,717
Weighted Average Interest Rate	2.17%	2.79%
Weighted Average Days to Maturity | days	55	49

Derivative and Other Hedging _3

Derivative and Other Hedging Instruments (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)month	Dec. 31, 2018USD ($)month	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Interest Rate Swaption [Member]
Average Maturity (Years)	9 years 6 months	7 years 4 months 24 days
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration | month	11	6
Notional Amount	$ 8,850	$ 3,500
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(26)	90	$ (66)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	7,650	1,250	6,450
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	$ (2,300)	$ (4,400)	(1,000)
Derivative, Average Fixed Interest Rate	2.34%	2.93%
Interest Rate Derivatives, at Fair Value, Net	$ 126	$ 37
Options At Cost	176	98
TBA and Forward Settling Agency Securities [Member]
Notional Amount	7,322	7,152	15,474	$ 10,916
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	411	(299)	330
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	95,169	194,534	237,601
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		(202,856)	(233,043)
US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(109)	48	0
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(2,325)	(181)	191
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Notional Amount	8,850
Short [Member] | US Treasury Securities [Member]
Notional Amount	9,224	21,345	10,699	8,061
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(967)	(161)	(141)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	12,601	19,278	14,030
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	24,722	(8,632)	(11,392)
Long [Member] | US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	11	1	1
Trading Securities Added During the Period	1,776	1,949	404
Notional Amount Of Trading Securities Settlement Expiration During The Period	(1,726)	(1,904)	(593)
Debt Securities, Trading, and Equity Securities, FV-NI		$ 45	$ 0	$ 189
Long [Member]
Debt Securities, Trading, and Equity Securities, FV-NI	$ 95

Derivative and Other Hedging _4

Derivative and Other Hedging Instruments (Fair Value Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative asset, fair value	$ 190	$ 273
Derivative liability, fair value	(6)	(84)
Derivative assets, at fair value	(190)	(273)
Derivative Liability	(6)	(84)
U.S. Treasury securities	97	46
U.S. Treasury Securities - short	(9,543)	(21,431)
Total - (short)/long, net	(9,446)	(21,385)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(2,325)	(181)	$ 191
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	7,322	7,152	15,474	$ 10,916
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	95,169	194,534	237,601
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		(202,856)	(233,043)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	411	(299)	330
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	79,075	51,625
Derivative liability, fair value	(2)	0
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	166,975	14,350	14,825
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(139,525)	(6,425)	(8,300)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(1,645)	140	67
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	21	126
Interest Rate Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	8,850	3,500
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	7,650	1,250	6,450
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(2,300)	(4,400)	(1,000)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(26)	90	(66)
Interest Rate Swaption [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	126	37
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative liability, fair value	(4)	(40)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(94,999)
US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(109)	48	0
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Future [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative [Line Items]
Derivative assets, at fair value	14	0
Derivative Liability	0	(44)
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	(29)	(110)
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	79,075
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	8,850
Short [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	9,224	21,345	10,699	8,061
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	12,601	19,278	14,030
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	24,722	(8,632)	(11,392)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(967)	(161)	(141)
Long [Member]
Derivative [Line Items]
Debt Securities, Trading, and Equity Securities, FV-NI	95
Long [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	11	1	1
Debt Securities, Trading, and Equity Securities, FV-NI		45	0	$ 189
Trading Securities Added During the Period	1,776	1,949	404
Notional Amount Of Trading Securities Settlement Expiration During The Period	$ (1,726)	$ (1,904)	$ (593)

Derivative and Other Hedging _5

Derivative and Other Hedging Instruments (Summary Of Outstanding Interest Rate Swaps) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)month	Dec. 31, 2018USD ($)month	Dec. 31, 2017USD ($)
Interest Rate Swaps Linked to Overnight Index Swap Rate	86.00%	0.00%
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (2,325)	$ (181)	$ 191
Interest Rate Swaps Linked to 3-Month LIBOR	11.00%	100.00%
Interest Rate Swaps Linked to Secured Overnight Financing Rate	3.00%	0.00%
Payer Swaption [Member]
Interest Rate Derivative Not Designated As Hedging Instruments Receive Rate	3M	3M
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (26)	$ 90	(66)
Notional Amount	$ 8,850	$ 3,500
Average Fixed Pay Rate	2.34%	2.93%
Options At Cost	$ 176	$ 98
Interest Rate Derivatives, at Fair Value, Net	$ 126	$ 37
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration | month	11	6
Average Maturity (Years)	9 years 6 months	7 years 4 months 24 days
Forward Contracts [Member] | Interest Rate Swap [Member]
Derivative, Notional Amount		$ 5,700
Weighted Average Forward Start Date		6 months
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (1,645)	$ 140	$ 67
Notional Amount	$ 79,075	$ 51,625
Average Fixed Pay Rate	1.29%	2.11%
Average Receive Rate	1.59%	2.63%
Average Maturity (Years)	2 years 8 months 12 days	5 years
Less Than or Equal to One Year [Member] | Payer Swaption [Member]
Interest Rate Derivative Not Designated As Hedging Instruments Receive Rate	3M	3M
Less Than or Equal to One Year [Member] | Interest Rate Swaption [Member]
Notional Amount	$ 5,650	$ 3,000
Average Fixed Pay Rate	2.26%	2.96%
Options At Cost	$ 123	$ 80
Interest Rate Derivatives, at Fair Value, Net	$ 80	$ 23
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration | month	8	4
Average Maturity (Years)	9 years 3 months 18 days	7 years
Greater Than One Year and Less Than or Equal to Two Years [Member] | Payer Swaption [Member]
Interest Rate Derivative Not Designated As Hedging Instruments Receive Rate	3M	3M
Greater Than One Year and Less Than or Equal to Two Years [Member] | Interest Rate Swaption [Member]
Notional Amount	$ 3,200	$ 500
Average Fixed Pay Rate	2.50%	2.78%
Options At Cost	$ 53	$ 18
Interest Rate Derivatives, at Fair Value, Net	$ 46	$ 14
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration | month	16	18
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	$ 59,700	$ 19,900
Average Fixed Pay Rate	1.30%	1.63%
Average Receive Rate	1.58%	2.62%
Average Maturity (Years)	1 year 7 months 6 days	1 year 3 months 18 days
Greater Than Three Years and Less Than or Equal to Five Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 9,850	$ 8,425
Average Fixed Pay Rate	1.17%	2.06%
Average Receive Rate	1.55%	2.61%
Average Maturity (Years)	3 years 9 months 18 days	4 years
Greater Than Five Years and Less than or Equal to Seven Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 5,650	$ 7,875
Average Fixed Pay Rate	1.34%	2.66%
Average Receive Rate	1.70%	2.66%
Average Maturity (Years)	6 years 4 months 24 days	6 years 1 month 6 days
Greater Than Seven Years and Less than or Equal to Ten Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 2,850	$ 10,550
Average Fixed Pay Rate	1.36%	2.36%
Average Receive Rate	1.58%	2.64%
Average Maturity (Years)	8 years 10 months 24 days	8 years 9 months 18 days
Greater Than Ten Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 1,025	$ 4,875
Average Fixed Pay Rate	1.64%	2.77%
Average Receive Rate	1.78%	2.63%
Average Maturity (Years)	15 years 4 months 24 days	11 years 7 months 6 days

Derivative and Other Hedging _6

Derivative and Other Hedging Instruments (Remaining Interest Rate Swap Term) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)month	Dec. 31, 2018USD ($)month	Dec. 31, 2017USD ($)
Interest Rate Swaps Linked to 3-Month LIBOR	11.00%	100.00%
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (2,325)	$ (181)	$ 191
Interest Rate Swaps Linked to Overnight Index Swap Rate	86.00%	0.00%
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (26)	$ 90	(66)
Cost	176	98
Fair Value	$ 126	$ 37
Average Months to Expiration | month	11	6
Derivative Liability, Notional Amount	$ 8,850	$ 3,500
Average Fixed Pay Rate	2.34%	2.93%
Average Maturity (Years)	9 years 6 months	7 years 4 months 24 days
Payer Swaption [Member]
Average Receive Rate (LIBOR)	3M	3M
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (1,645)	$ 140	$ 67
Derivative Liability, Notional Amount	$ 79,075	$ 51,625
Average Fixed Pay Rate	1.29%	2.11%
Average Maturity (Years)	2 years 8 months 12 days	5 years
Less Than or Equal to One Year [Member] | Interest Rate Swaption [Member]
Cost	$ 123	$ 80
Fair Value	$ 80	$ 23
Average Months to Expiration | month	8	4
Derivative Liability, Notional Amount	$ 5,650	$ 3,000
Average Fixed Pay Rate	2.26%	2.96%
Average Maturity (Years)	9 years 3 months 18 days	7 years
Less Than or Equal to One Year [Member] | Payer Swaption [Member]
Average Receive Rate (LIBOR)	3M	3M
Greater Than One Year and Less Than or Equal to Three Years [Member] | Interest Rate Swap [Member]
Derivative Liability, Notional Amount	$ 59,700	$ 19,900
Average Fixed Pay Rate	1.30%	1.63%
Average Maturity (Years)	1 year 7 months 6 days	1 year 3 months 18 days
Bermudan [Member] | Interest Rate Swaption [Member]
Derivative Liability, Notional Amount	$ 700
Interest Rate Swaps Excluding Forward Starting [Member] | Interest Rate Swap [Member]
Average Fixed Pay Rate		1.98%

Derivative and Other Hedging _7

Derivative and Other Hedging Instruments (US Treasury Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
U.S. Treasury securities, net	$ (9,446)	$ (21,385)
Weighted Average Yield Percentage	3.07%	3.31%
7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	$ 0	$ (14,357)
At Par Value [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(9,129)	(21,300)
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(7,322)	(7,152)
Derivative, Forward Settlement Value	(7,404)	(7,252)
Derivative Asset, Fair Value, Gross Asset	(7,429)	(7,322)
Derivative, Fair Value, Net	25	70
5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	95	(703)
10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(9,224)	(6,240)
10 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	14	(44)
Short [Member] | 10 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,000)	(1,650)
Derivative, Forward Settlement Value	(1,298)	(1,969)
Derivative Asset, Fair Value, Gross Asset	(1,284)	(2,013)
Fair Value Hedging [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(9,446)	(21,385)
Fair Value Hedging [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	0	(14,410)
Fair Value Hedging [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	97	(713)
Fair Value Hedging [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(9,543)	(6,262)
At Cost Basis [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(9,234)	(21,255)
At Cost Basis [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	0	(14,325)
At Cost Basis [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	95	(706)
At Cost Basis [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	$ (9,329)	$ (6,224)
US Treasury Securities [Member] | Short [Member]
Derivative [Line Items]
Weighted Average Yield Percentage	2.19%	2.66%
US Treasury Securities [Member] | Long [Member]
Derivative [Line Items]
Weighted Average Yield Percentage	2.21%	2.98%

Derivative and Other Hedging _8

Derivative and Other Hedging Instruments (TBA Securities by Coupon and Issuer) (Details) - TBA and Forward Settling Agency Securities [Member] - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative, Notional Amount	$ 7,322	$ 7,152
Cost Basis	(7,404)	(7,252)
Net long TBA position, at fair value	(7,429)	(7,322)
TBA, net carrying value	25	70
30 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	5,142	3,529
Cost Basis	(5,182)	(3,617)
Net long TBA position, at fair value	(5,203)	(3,649)
TBA, net carrying value	21	32
30 Year Maturity [Member] | 3.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	5,008	1,028
Cost Basis	(5,052)	(981)
Net long TBA position, at fair value	(5,073)	(1,003)
TBA, net carrying value	21	22
30 Year Maturity [Member] | 3.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,226
Cost Basis	(1,259)
Net long TBA position, at fair value	(1,261)
TBA, net carrying value	2	(34)
30 Year Maturity [Member] | 4.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount		3,030
Cost Basis		(3,073)
Net long TBA position, at fair value		(3,089)
TBA, net carrying value	(3)	16
30 Year Maturity [Member] | 4.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	415	2,450
Cost Basis	(436)	(2,506)
Net long TBA position, at fair value	(437)	(2,534)
TBA, net carrying value	1	28
30 Year Maturity [Member] | Short [Member] | 3.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount		2,979
Cost Basis		(2,943)
Net long TBA position, at fair value		(2,977)
30 Year Maturity [Member] | Short [Member] | 4.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,507
Cost Basis	(1,565)
Net long TBA position, at fair value	(1,568)
15 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	2,180	3,623
Cost Basis	(2,222)	(3,635)
Net long TBA position, at fair value	(2,226)	(3,673)
TBA, net carrying value	4	38
15 Year Maturity [Member] | 2.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	805	0
Cost Basis	(811)	0
Net long TBA position, at fair value	(812)	0
TBA, net carrying value	1	0
15 Year Maturity [Member] | 3.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,059	567
Cost Basis	(1,083)	(557)
Net long TBA position, at fair value	(1,086)	(566)
TBA, net carrying value	3	9
15 Year Maturity [Member] | 3.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	241	1,706
Cost Basis	(250)	(1,708)
Net long TBA position, at fair value	(250)	(1,726)
TBA, net carrying value	0	18
15 Year Maturity [Member] | 4.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	75	1,350
Cost Basis	(78)	(1,370)
Net long TBA position, at fair value	(78)	(1,381)
TBA, net carrying value	$ 0	$ 11

Derivative and Other Hedging _9

Derivative and Other Hedging Instruments (Effect Of Derivative Instruments Not Designated As Hedges On Comprehensive Income Statement) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	$ (2,325)	$ (181)	$ 191
Interest rate swap - receiver [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Additions	175
Settlement, Expirations or Exercise	(175)
Amount Gain/(Loss) Recognized in Income on Derivatives	0
Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(3,500)
Additions	(7,650)	(1,250)	(6,450)
Settlement, Expirations or Exercise	2,300	4,400	1,000
Notional Amount	(8,850)	(3,500)
Amount Gain/(Loss) Recognized in Income on Derivatives	(26)	90	(66)
TBA and Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(7,152)	(15,474)	(10,916)
Additions	(95,169)	(194,534)	(237,601)
Settlement, Expirations or Exercise		202,856	233,043
Notional Amount	(7,322)	(7,152)	(15,474)
Amount Gain/(Loss) Recognized in Income on Derivatives	411	(299)	330
Derivative, Notional Amount	(7,322)	(7,152)
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Settlement, Expirations or Exercise	94,999
Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(51,625)
Additions	(166,975)	(14,350)	(14,825)
Settlement, Expirations or Exercise	139,525	6,425	8,300
Notional Amount	(79,075)	(51,625)
Amount Gain/(Loss) Recognized in Income on Derivatives	(1,645)	140	67
US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	(109)	48	0
Not Designated as Hedging Instrument [Member] | Interest rate swap - receiver [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	0
Derivative, Notional Amount		0
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(8,850)
Derivative, Notional Amount		(3,500)	(6,650)	$ (1,200)
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(79,075)
Derivative, Notional Amount		(51,625)	(43,700)	(37,175)
Short [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(21,345)	(10,699)	(8,061)
Additions	(12,601)	(19,278)	(14,030)
Settlement, Expirations or Exercise	(24,722)	8,632	11,392
Notional Amount	(9,224)	(21,345)	(10,699)
Amount Gain/(Loss) Recognized in Income on Derivatives	(967)	(161)	(141)
Long [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Debt Securities, Trading, and Equity Securities, FV-NI	95
Long [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	11	1	1
Debt Securities, Trading, and Equity Securities, FV-NI		45	0	$ 189
Trading Securities Added During the Period	1,776	1,949	404
Notional Amount Of Trading Securities Settlement Expiration During The Period	(1,726)	(1,904)	(593)
Future [Member] | Short [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(1,650)	(2,910)	(1,810)
Additions	5,300	(7,859)	(11,340)
Settlement, Expirations or Exercise	(5,950)	9,119	10,240
Notional Amount	$ (1,000)	$ (1,650)	$ (2,910)

Pledged Assets (Narrative) (Det

Pledged Assets (Narrative) (Details)	Dec. 31, 2019
Pledged Assets [Abstract]
Risk Of Repurchase Agreement To Stockholders Equity	4.00%

Pledged Assets Repurchase Agree

Pledged Assets Repurchase Agreements with Counterparties Greater than or Equal to 5% of Equity at Risk (Details) $ in Millions	Dec. 31, 2019USD ($)days	Dec. 31, 2018USD ($)days
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Securities Sold under Agreements to Repurchase | $	$ 89,182	$ 75,717
Risk Of Repurchase Agreement To Stockholders Equity	4.00%
Weighted Average Days to Maturity | days	55	49
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	10.00%

Pledged Assets (Assets Pledged

Pledged Assets (Assets Pledged as Collateral) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	$ 92,547	$ 79,182
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repurchase Agreements	144	163
Accrued interest on pledged securities	270	248
Restricted cash and cash equivalents	451	599
Total Fair Value of Securities Pledged and Accrued Interest	94,634
Total Fair Value Of Agency Securities Pledged And Accrued Interest		81,210
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	92,142	78,997
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	404	174
Accrued interest on pledged securities		1
Restricted cash and cash equivalents	340	522
Total Fair Value of Securities Pledged and Accrued Interest	745
Total Fair Value Of Agency Securities Pledged And Accrued Interest		697
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Accrued interest on pledged securities	267	246
Total Fair Value of Securities Pledged and Accrued Interest	93,282
Total Fair Value Of Agency Securities Pledged And Accrued Interest		79,943
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	371	436
Accrued interest on pledged securities	1	1
Total Fair Value of Securities Pledged and Accrued Interest	372
Total Fair Value Of Agency Securities Pledged And Accrued Interest		437
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	206	133
Accrued interest on pledged securities	1	0
Total Fair Value of Securities Pledged and Accrued Interest	235
Total Fair Value Of Agency Securities Pledged And Accrued Interest		133
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	93,123	79,740
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	309	141
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	309	141
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		45
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		45
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
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	481	437
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	28
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	453	437
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	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 and cash equivalents	111	77
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash and cash equivalents	0	0
Excluding Cash Received [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash and cash equivalents	$ 451	$ 599

Pledged Assets (Securities Pled

Pledged Assets (Securities Pledged as Collateral) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Offsetting Assets and Liabilities [Line Items]
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repo	$ 144	$ 163
Security Owned and Pledged as Collateral, Fair Value	92,547	79,182
Agency Securities Pledged As Collateral Amortized Cost	90,887	80,386
Agency Securities Pledged As Collateral Accrued Interest	267	247
Maturity Less than 30 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	56,990	49,944
Agency Securities Pledged As Collateral Amortized Cost	55,951	50,654
Agency Securities Pledged As Collateral Accrued Interest	167	156
Maturity 31 To 59 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	14,410	14,586
Agency Securities Pledged As Collateral Amortized Cost	14,114	14,810
Agency Securities Pledged As Collateral Accrued Interest	42	46
Maturity 60 To 90 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	7,637	7,770
Agency Securities Pledged As Collateral Amortized Cost	7,536	7,843
Agency Securities Pledged As Collateral Accrued Interest	20	24
Maturity over 90 days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	13,510	6,882
Agency Securities Pledged As Collateral Amortized Cost	13,286	7,079
Agency Securities Pledged As Collateral Accrued Interest	38	21
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	92,142	78,997
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	404	174
Credit Risk Transfer Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	309	141
Credit Risk Transfer Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	309	141
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	481	437
Securities Received as Collateral, Amount Repledged and Sold	357	437
US Treasury Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	453	437
US Treasury Securities [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 0	0
Non-Agency [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value		45
Non-Agency [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value		45
Non-Agency [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value		$ 0

Pledged Assets (Assets Pledge_2

Pledged Assets (Assets Pledged from Counterparties) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Offsetting Assets and Liabilities [Line Items]
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 9,543	$ 21,431
Restricted Cash and Cash Equivalents	451	599
Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	116	129
Restricted Cash and Securities Pledged	10,216	22,077
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	1	37
Restricted Cash and Cash Equivalents	0
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	1	37
Derivative [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Securities Pledged	116	164
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	10,100	21,948
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	10,099	21,876
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	10,099	21,876
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	340	522
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	35
Derivative [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	$ 116	$ 129

Pledged Assets (Offsetting Asse

Pledged Assets (Offsetting Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Offsetting Assets and Liabilities [Line Items]
Collateral Received	$ (445)
Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	10,357	$ 22,086
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	10,357	22,086
Financial Instruments	(9,858)	(17,276)
Collateral Received		(4,733)
Net Amount	54	77
Assets [Member] | ERROR in label resolution.
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	147	163
Net Amounts of Assets Presented in the Consolidated Balance Sheets	147	163
Financial Instruments	(2)	0
Collateral Received	(116)	(158)
Net Amount	29	5
Assets [Member] | TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	29	110
Net Amounts of Assets Presented in the Consolidated Balance Sheets	29	110
Financial Instruments	(4)	(40)
Net Amount	25	70
Assets [Member] | Reverse Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Net Amount	0	2
Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	89,188	75,757
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	89,188	75,757
Financial Instruments	(9,858)	(17,276)
Collateral Received	(79,330)	(58,481)
Net Amount	0
Liability [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Net Amount	0	0
Liability [Member] | ERROR in label resolution.
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	2	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	2	0
Financial Instruments	(2)	0
Collateral Received	0	0
Net Amount	0	0
Liability [Member] | TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	4	40
Net Amounts of Assets Presented in the Consolidated Balance Sheets	4	40
Financial Instruments	(4)	(40)
Collateral Received	0	0
Net Amount	0	0
Reverse Repurchase Agreements [Member] | Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	10,181	21,813
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	10,181	21,813
Financial Instruments	(9,852)	(17,236)
Collateral Received	(329)	(4,575)
Repurchase Agreements [Member] | Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	89,182	75,717
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	89,182	75,717
Financial Instruments	(9,852)	(17,236)
Collateral Received	$ (79,330)	$ (58,481)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
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]
TBA securities	$ 14	$ 0
Derivative Liability	0	44
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	126	37
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	21	126
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	2	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	$ (29)	(110)
Transfers between hierarchy levels	0
Agency securities	$ 98,516	82,291
Agency securities transferred to consolidated VIEs	371	436
Non-Agency Securities, at Fair Value	579	548
Financial Instruments, Owned, Other, at Fair Value	976	1,012
U.S. Treasury securities	97	46
TBA securities	(190)	(273)
Derivative Liability	6	84
Debt of consolidated variable interest entities, at fair value	228	275
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	9,543	21,431
Interest rate swaps	190	273
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	111	46
Total liabilities	9,543	21,475
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	100,618	84,560
Total liabilities	234	315
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	$ 4	$ 40

Net Income (Loss) Per Common _2

Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average Number of Shares Outstanding									540.2	440.9	358.6
Weighted Average Number of Fully Vested Restricted Stock Units and Performance Share Units Outstanding									0.4	0.2	0
Weighted Average Number of Shares Outstanding, Basic	541.4	546.4	537.8	536.7		462.3	404.9	391.3	540.6	441.1	358.6
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									0.8	0.3	0.1
Weighted Average Number of Shares Outstanding, Diluted	542.6	546.4	537.8	537.2	504.2	462.7	405.2	391.5	541.4	441.4	358.7
Net Income (Loss) Available to Common Stockholders, Basic	$ 847	$ (17)	$ (457)	$ 255	$ (813)	$ 207	$ 284	$ 415	$ 628	$ 93	$ 733
Earnings Per Share, Basic	$ 1.56	$ (0.03)	$ (0.85)	$ 0.48	$ (1.61)	$ 0.45	$ 0.70	$ 1.06	$ 1.16	$ 0.21	$ 2.04
Earnings Per Share, Diluted	$ 1.56	$ (0.03)	$ (0.85)	$ 0.47					$ 1.16	$ 0.21	$ 2.04

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	Oct. 03, 2019	Aug. 16, 2017	May 31, 2014	Dec. 31, 2019	Dec. 31, 2012	Nov. 26, 2019	Dec. 31, 2018	Apr. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock E, Value, Issued	$ 390
Preferred Stock E, Liquidation Preference, Value	$ 403
Preferred Stock D, Value, Issued				$ 227
Preferred Stock D, Liquidation Preference, Value				235
Preferred Stock C, Value, Issued				315
Preferred Stock C, Liquidation Preference, Value				325
Preferred Stock, Value, Issued				932			$ 484
Preferred Stock, Liquidation Preference, Value				$ 963			$ 500
Preferred Stock, Shares Authorized				10,000,000
Series A Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Dividend Rate, Percentage					8.00%
Preferred Stock, Liquidation Preference Per Share								$ 25
Payments for Repurchase of Redeemable Preferred Stock		$ 173
Series B Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Percent Interest Per Share			0.10%
Preferred Stock, Capital Shares Reserved for Future Issuance							8,050
Preferred Stock, Dividend Rate, Percentage				7.75%
Preferred Stock, Liquidation Preference Per Share						$ 25
Preferred Stock, Shares Issued							7,000
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
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				4.30%
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
Depositary Share [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued				38,500,000
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
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

Stockholders' Equity (Common St

Stockholders' Equity (Common Stock Repurchase Program) (Details) - USD ($) shares in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jul. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchase Program, Authorized Amount				$ 1,000,000,000
Repurchase of common stock shares	(6.9)
Repurchase of common stock, value	$ 103,000,000
Payments for Repurchase of Common Stock	103,000,000	$ 0	$ 0
Stock Repurchased During Period, Average Repurchase Price (in dollars per share)	14.90
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 900,000,000
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of common stock shares	(6.9)

Stockholders' Equity (Accumulat

Stockholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
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	$ 15	$ 246	$ 379	$ 400	$ 361	$ (193)	$ (145)	$ (621)	$ 1,040	$ (598)	$ 52
Agency Securities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning OCI Balance				$ (943)				$ (345)	(943)	(345)	(397)
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax									1,031	(677)	(31)
Amounts reclassified from accumulated OCI									9	79	83
Ending OCI Balance	$ 97				$ (943)				$ 97	$ (943)	$ (345)

Stockholders' Equity (Follow-On

Stockholders' Equity (Follow-On Equity Offerings) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Nov. 19, 2018	Aug. 03, 2018	May 29, 2018	Sep. 12, 2017	May 05, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Sale of Stock, Price Per Share	$ 17.09	$ 18.68	$ 18.35	$ 20.47	$ 20.51	$ 16.67	$ 18.03	$ 20.96
Stock Issued During Period, Shares, New Issues	46	43.7	34.5	28.2	24.5	11.4	20.8	7.6
Stock Issued During Period, Value, New Issues	$ 786	$ 817	$ 633	$ 577	$ 503	$ 190	$ 2,611	$ 1,238
Follow-On Public Offering [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues							124.2	52.7
Stock Issued During Period, Value, New Issues							$ 2,236	$ 1,080

Stockholders' Equity (At-the-Ma

Stockholders' Equity (At-the-Market Offering Program) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Nov. 19, 2018	Aug. 03, 2018	May 29, 2018	Sep. 12, 2017	May 05, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares Authorized						$ 466
Stock Issued During Period, Shares, New Issues	46	43.7	34.5	28.2	24.5	11.4	20.8	7.6
Stock Issued During Period, Value, New Issues	$ 786	$ 817	$ 633	$ 577	$ 503	$ 190	$ 2,611	$ 1,238
Sale of Stock, Price Per Share	$ 17.09	$ 18.68	$ 18.35	$ 20.47	$ 20.51	$ 16.67	$ 18.03	$ 20.96
Common Stock At The Market Sale Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Value, New Issues						$ 190	$ 375	$ 159

Stockholders' Equity (Dividend

Stockholders' Equity (Dividend Reinvestment and Direct Stock Purchase Plan) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock			$ 9
Preferred Stock, Dividend Rate, Per-Dollar-Amount			$ 1.333000
Dividends, Common Stock	$ 1,081	$ 964	$ 777
Common Stock, Dividends, Per Share, Cash Paid	$ 2	$ 2.160000	$ 2.160000
Preferred Class B [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 12	$ 14	$ 14
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 1.673785	$ 1.937500	$ 1.937500
Series C Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 23	$ 23	$ 9
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 1.750000	$ 1.750000	$ 0.695140
Series D Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 14
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 1.475263
Series E Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 7
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 0.460420

Stockholders' Equity Schedule o

Stockholders' Equity Schedule of Dividends Declared (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock			$ 9
Preferred Stock, Dividend Rate, Per-Dollar-Amount			$ 1.333000
Dividends, Common Stock	$ 1,081	$ 964	$ 777
Common Stock, Dividends, Per Share, Cash Paid	$ 2	$ 2.160000	$ 2.160000
Preferred Class B [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 12	$ 14	$ 14
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 1.673785	$ 1.937500	$ 1.937500
Series C Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 23	$ 23	$ 9
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 1.750000	$ 1.750000	$ 0.695140
Series D Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 14
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 1.475263
Series E Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 7
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 0.460420

Equity Incentive Plan Narrative

Equity Incentive Plan Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value			$ 0	$ 17.49
Restricted Stock Award, Forfeitures	(4,224)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 15.84
Accrued RSU Dividend Equivalents			1,032
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value			$ 16.69
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Vest Date Fair Value			$ 20.15
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 15,000,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 6 months
2016 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		10,000,000
Restricted Stock or Unit Expense		$ 185,285
Deferred Compensation Share-based Arrangements, Liability, Current and Noncurrent	400,000
Share-based Payment Arrangement, Expense	$ 13,700,000	$ 6,100,000	$ 3,100,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	6,400,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 15.44	$ 16.08	$ 17.46	$ 17.72
Accrued RSU Dividend Equivalents	83,355	56,618	32,498
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 15.30	$ 16.52	$ 16.08
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Vest Date Fair Value	$ 17.91	$ 18.60	$ 20.42
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(6,812)	(546)	(246)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 16	$ 16.98	$ 18.29
Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	$ 500,000	$ 500,000	$ 500,000
MTGE Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense		$ 5,000,000	$ 1,000,000
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			0	21,435
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			(22,467)
Restricted Stock Units (RSUs) [Member] | 2016 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	758,230	501,913	335,228	102,375
Restricted Stock or Unit Expense	$ 7,000,000	$ 4,000,000	$ 4,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	432,149	261,036	238,203
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 17.59	$ 18.05	$ 19.52
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(252,375)	(150,423)	(37,602)
Restricted Stock Units (RSUs) [Member] | MTGE Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock or Unit Expense		$ 2,000,000	$ 2,000,000
Performance Shares [Member] | 2016 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 14.96	$ 16.08	$ 17.78
Performance Adjustment - Accrued PSU Dividend Equivalents	35,825
Accrued RSU Dividend Equivalents	123,594	61,171	22,767
Performance Shares [Member] | Restricted Stock Units (RSUs) [Member] | 2016 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	1,351,413	606,775	273,376
Restricted Stock or Unit Expense	$ 9,000,000	$ 5,000,000	$ 5,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	494,016	272,228	250,609
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 17.56	$ 17.98	$ 19.39
Director [Member] | Restricted Stock Units (RSUs) [Member] | 2016 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock or Unit Expense	$ 500,000	$ 500,000	$ 500,000
Performance adjustment [Member] | Performance Shares [Member] | Restricted Stock Units (RSUs) [Member] | 2016 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	95,427
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 19.39
Share Distribution [Member] | Restricted Stock Units (RSUs) [Member] | MTGE Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock or Unit Expense	$ 4,000,000

Income Taxes (Details)

Income Taxes (Details)	12 Months Ended
	Dec. 31, 2019
Investments, Owned, Federal Income Tax Note [Line Items]
Required Annual Distribution of Taxable Net Income	90.00%

Quarterly Results (Details)

Quarterly Results (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income	$ 768	$ 676	$ 693	$ 705	$ 604	$ 500	$ 414	$ 431	$ 2,842	$ 1,949	$ 1,293
Interest expense	481	557	570	541	418	312	237	206	2,149	1,173	524
Net interest income	287	119	123	164	186	188	177	225	693	776	769
Noninterest Income [Abstract]
Gain (loss) on sale of investment securities, net	107	89	132	60	(21)	(40)	(74)	(2)	388	(137)	(63)
Unrealized gain (loss) on investment securities measured at fair value through net income, net	(160)	355	759	1,060	683	(363)	(94)	(523)	2,014	(297)	(71)
(Loss) gain on derivative instruments and other securities, net	$ 662	$ (548)	$ (1,438)	$ (1,000)	(1,633)	430	298	738	(2,324)	(167)	193
Management Fee Income					$ 0	$ 46	$ 4	$ 4	$ 0	$ 54	$ 16
Weighted Average Number of Shares Outstanding, Diluted	542.6	546.4	537.8	537.2	504.2	462.7	405.2	391.5	541.4	441.4	358.7
Earnings Per Share, Basic	$ 1.56	$ (0.03)	$ (0.85)	$ 0.48	$ (1.61)	$ 0.45	$ 0.70	$ 1.06	$ 1.16	$ 0.21	$ 2.04
Comprehensive income per share - basic and diluted					$ (0.90)	$ 0.03	$ 0.34	$ (0.53)
Earnings Per Share, Diluted	1.56	(0.03)	(0.85)	0.47					$ 1.16	$ 0.21	$ 2.04
Comprehensive income per share - basic	1.59	0.42	(0.15)	1.22
Comprehensive income per share - diluted	$ 1.59	$ 0.42	$ (0.15)	$ 1.22
Total other (loss) income, net	$ 609	$ (104)	$ (547)	$ 120	$ (971)	$ 73	$ 134	$ 217	$ 78	$ (547)	$ 75
Labor and Related Expense	16	10	11	10	11	14	10	10	47	45	42
General and administrative expenses	9	9	9	9	8	31	8	8	36	55	31
Total expenses	25	19	20	19	19	45	18	18	83	100	73
Net income (loss)	871	(4)	(444)	265	(804)	216	293	424	688	129	771
Dividend on preferred stock	18	13	13	10	9	9	9	9	54	36	32
Net income (loss) available (attributable) to common shareholders	847	(17)	(457)	255	(813)	207	284	415	628	93	733
Unrealized Gains and (Losses), Net	15	246	379	400	361	$ (193)	$ (145)	$ (621)	1,040	(598)	52
Issuance costs of redeemed preferred stock	$ 6	$ 0	$ 0	$ 0					$ 6	$ 0	$ 6
Weighted Average Number of Shares Outstanding, Basic	541.4	546.4	537.8	536.7		462.3	404.9	391.3	540.6	441.1	358.6
Comprehensive (loss) income	$ 886	$ 242	$ (65)	$ 665	(443)	$ 23	$ 148	$ (197)	$ 1,728	$ (469)	$ 823
Comprehensive (loss) income (attributable) available to common shareholders	$ 862	$ 229	$ (78)	$ 655	$ (452)	$ 14	$ 139	$ (206)	$ 1,668	$ (505)	$ 785
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Common Stock, Dividends, Per Share, Declared	$ 0.48	$ 0.48	$ 0.50	$ 0.54	$ 0.54	$ 0.54	$ 0.54	$ 0.54

Subsequent Event (Details)

Subsequent Event (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Feb. 13, 2020	Feb. 11, 2020	Nov. 19, 2018	Aug. 03, 2018	May 29, 2018	Sep. 12, 2017	May 05, 2017	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 03, 2019	Jul. 31, 2019
Subsequent Event [Line Items]
Preferred Stock, Liquidation Preference, Value								$ 963				$ 500				$ 963	$ 500
Preferred Stock D, Value, Issued								$ 227								227
Preferred Stock E, Value, Issued																			$ 390
Preferred Stock E, Liquidation Preference, Value																			$ 403
Dividends, Preferred Stock, Cash																$ 54	$ 36	$ 32
Common Stock, Dividends, Per Share, Declared								$ 0.48	$ 0.48	$ 0.50	$ 0.54	$ 0.54	$ 0.54	$ 0.54	$ 0.54
Stock Issued During Period, Shares, New Issues			46	43.7	34.5	28.2	24.5									11.4	20.8	7.6
Stock Issued During Period, Value, New Issues			$ 786	$ 817	$ 633	$ 577	$ 503									$ 190	$ 2,611	$ 1,238
Sale of Stock, Price Per Share			$ 17.09	$ 18.68	$ 18.35	$ 20.47	$ 20.51	$ 16.67				$ 18.03				$ 16.67	$ 18.03	$ 20.96
Stock Repurchase Program, Authorized Amount																				$ 1,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.16
Common Stock [Member]
Subsequent Event [Line Items]
Stock Issued During Period, Shares, New Issues																11.4	145	60.3
Stock Issued During Period, Value, New Issues																	$ 1	$ 1
Series F Preferred Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Preferred Stock, Liquidation Preference, Value		$ 575
Preferred Stock, Dividend Rate, Percentage		6.125%
Preferred Stock D, Value, Issued		$ 557
Preferred Stock Dividend Payment Rate Variable Rate Spread		4.697%
Preferred Stock, Liquidation Preference Per Share		$ 25
Depositary Share [Member]
Subsequent Event [Line Items]
Preferred Stock, Shares Issued								38.5								38.5
Depositary Share [Member] | Series F Preferred Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Preferred Stock, Shares Issued		23

Uncategorized Items - agnc10k12

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