AGNC Investment (AGNC) 10-K 27 Feb 17 2016 Q4 Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2016	Jan. 31, 2017	Jun. 30, 2016
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q4
Entity Registrant Name	AGNC Investment Corp.
Entity Central Index Key	1,423,689
Entity Filer Category	Large Accelerated Filer
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		331,046,077
Trading Symbol	AGNC
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 5.5

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Assets:
Agency securities, at fair value (including pledged securities of $43,943 and $48,380, respectively)	$ 45,393	$ 51,331
Agency securities transferred to consolidated variable interest entities, at fair value (pledged securities)	818	1,029
Non-agency securities, at fair value (including pledged securities of $90 and $113, respectively)	124	113
Credit risk transfer securities, at fair value	164	0
U.S. Treasury securities, at fair value (including pledged securities of $173 and $25, respectively)	182	25
REIT equity securities, at fair value	0	33
Cash and cash equivalents	1,208	1,110
Restricted cash and cash equivalents	74	1,281
Derivative assets, at fair value	355	81
Receivable for securities sold (pledged securities)	21	0
Receivable under reverse repurchase agreements	7,716	1,713
Goodwill and other intangible assets, net	554	0
Other assets	271	305
Total assets	56,880	57,021
Liabilities:
Repurchase Agreements	37,858	41,754
Federal Home Loan Bank advances	3,037	3,753
Debt of consolidated variable interest entities, at fair value	460	595
Payable for securities purchased	0	182
Derivative liabilities, at fair value	256	935
Dividends payable	66	74
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	7,636	1,696
Accounts payable and other liabilities	211	61
Total liabilities	49,524	49,050
Stockholders' equity:
Preferred stock - $0.01 par value; 10.0 shares authorized: Redeemable Preferred Stock; $0.01 par value; 6.9 shares issued and outstanding (aggregate liquidation preference of $348)	336	336
Common stock - $0.01 par value; 600.0 shares authorized; 331.0 and 337.5 shares issued and outstanding, respectively	3	3
Additional paid-in capital	9,932	10,048
Retained deficit	(2,518)	(2,350)
Accumulated other comprehensive loss	(397)	(66)
Total stockholders' equity	7,356	7,971
Total liabilities and stockholders' equity	$ 56,880	$ 57,021

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Available-for-sale Securities Pledged as Collateral	$ 43,943	$ 48,380
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	10	10
Preferred Stock, Shares Issued	6.9	6.9
Preferred Stock, Shares Outstanding	6.9	6.9
Preferred Stock, Liquidation Preference, Value	$ 348	$ 348
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01	$ 0.01
Common Stock, Shares Authorized	600	600
Common Stock, Shares, Issued	331	337.5
Common Stock, Shares, Outstanding	331	337.5
Non-Agency Securities Pledged as Collateral	$ 90	$ 113
Trading Securities Pledged as Collateral	$ 173	$ 25

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income:
Interest income	$ 393	$ 315	$ 318	$ 295	$ 374	$ 295	$ 414	$ 383	$ 1,321	$ 1,466	$ 1,472
Interest expense	98	96	101	99	86	77	81	86	394	330	372
Net interest income	295	219	217	196	288	218	333	297	927	1,136	1,100
Other income, net:
Gain (loss) on sale of agency securities, net	(5)	61	55	(2)	2	(39)	(22)	36	109	(23)	51
Unrealized gain (loss) on investment securities measured at fair value through net income, net	(11)	(6)	0	11	(9)	10	(7)	11	(6)	5	32
Loss on derivative instruments and other securities, net	753	248	(367)	(944)	340	(788)	244	(560)	(310)	(764)	(1,275)
Management fee income	4	4	0	0					8	0	0
Total other income, net	741	307	(312)	(935)	333	(817)	215	(513)	(199)	(782)	(1,192)
Expenses:
Management fees	0	0	25	27	28	29	29	30	52	116	119
Compensation and benefits	10	9	0	0					19	0	0
General and administrative expenses	7	6	15	6	5	5	7	6	34	23	22
Total expenses	17	15	40	33	33	34	36	36	105	139	141
Net Income (Loss) Attributable to Parent	1,019	511	(135)	(772)	588	(633)	512	(252)	623	215	(233)
Dividend on preferred stock	7	7	7	7	7	7	7	7	28	28	23
Net income (loss) available (attributable) to common stockholders	1,012	504	(142)	(779)	581	(640)	505	(259)	595	187	(256)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	1,408	97	(370)	(765)	583	(467)	872	(391)	370	597	(1,657)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, De-Designated Interest Rate Swaps									(39)	(101)	(156)
Unrealized gain on derivative instruments, net	1	7	12	19	22	24	26	29	39	101	156
Other comprehensive income (loss)	(1,407)	(90)	382	784	(561)	491	(846)	420	(331)	(496)	1,813
Comprehensive income (loss)	(388)	421	247	12	27	(142)	(334)	168	292	(281)	1,580
Comprehensive income (loss) available (attributable) to common stockholders	$ (395)	$ 414	$ 240	$ 5	$ 20	$ (149)	$ (341)	$ 161	$ 264	$ (309)	$ 1,557
Weighted average number of common shares outstanding-basic and diluted (shares)	331,000,000	331,000,000	331,000,000	334,400,000	341,600,000	347,800,000	352,100,000	352,800,000	331,900,000	348,600,000	353,300,000
Net income (loss) per common share - basic and diluted	$ 3.06	$ 1.52	$ (0.43)	$ (2.33)	$ 1.70	$ (1.84)	$ 1.43	$ (0.73)	$ 1.79	$ 0.54	$ (0.72)
Dividends declared per common share	$ 0.54	$ 0.56	$ 0.60	$ 0.60	$ 0.60	$ 0.60	$ 0.62	$ 0.66

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, 2013	$ 8,697	$ 167	$ 4	$ 10,406	$ (497)	$ (1,383)
Balance, Preferred Stock, shares at Dec. 31, 2013		6.9
Balance, Common Stock, shares at Dec. 31, 2013			356.2
Net income (loss)	(233)				(233)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	1,657					1,657
Amounts reclassified from accumulated OCI	156					156
Issuance of preferred stock	169	$ 169
Repurchase of common stock	(74)			(74)
Payments for Repurchase of Common Stock	$ 74
Repurchase of common stock shares	(3.4)		(3.4)
Preferred dividends declared	$ (23)				(23)
Common dividends declared	(921)				(921)
Balance, value at Dec. 31, 2014	9,428	$ 336	$ 4	10,332	(1,674)	430
Balance, Preferred Stock, shares at Dec. 31, 2014		6.9
Balance, Common Stock, shares at Dec. 31, 2014			352.8
Net income (loss)	215				215
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(597)					(597)
Amounts reclassified from accumulated OCI	101					101
Issuance of preferred stock	0
Repurchase of common stock	(285)		$ (1)	(284)
Payments for Repurchase of Common Stock	$ 285
Repurchase of common stock shares	(15.3)		(15.3)
Preferred dividends declared	$ (28)				(28)
Common dividends declared	(863)				(863)
Balance, value at Dec. 31, 2015	$ 7,971
Balance, Preferred Stock, shares at Dec. 31, 2015	6.9
Balance, Common Stock, shares at Dec. 31, 2015	337.5
Balance, value at Sep. 30, 2015	$ 7,971	$ 336	$ 3	10,048	(2,350)	(66)
Balance, Preferred Stock, shares at Sep. 30, 2015		6.9
Balance, Common Stock, shares at Sep. 30, 2015			337.5
Net income (loss)	588
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(583)
Amounts reclassified from accumulated OCI	22
Balance, value at Dec. 31, 2015	$ 7,971
Balance, Preferred Stock, shares at Dec. 31, 2015	6.9
Balance, Common Stock, shares at Dec. 31, 2015	337.5
Net income (loss)	$ 623				623
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(370)					(370)
Amounts reclassified from accumulated OCI	39					39
Issuance of preferred stock	0
Repurchase of common stock	(116)		$ 0	(116)
Payments for Repurchase of Common Stock	$ 116
Repurchase of common stock shares	(6.5)		(6.5)
Preferred dividends declared	$ (28)				(28)
Common dividends declared	(763)				(763)
Balance, value at Dec. 31, 2016	$ 7,356	$ 336	$ 3	$ 9,932	$ (2,518)	$ (397)
Balance, Preferred Stock, shares at Dec. 31, 2016	6.9	6.9
Balance, Common Stock, shares at Dec. 31, 2016	331		331

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Cash Flows [Abstract]
Interest Paid	$ 332	$ 215	$ 217
Operating activities:
Net income (loss)	623	215	(233)
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of premiums and discounts on mortgage-backed securities, net	400	408	472
Amortization of accumulated other comprehensive loss on interest rate swaps de-designated as qualifying hedges	39	101	156
Amortization of intangible assets	2	0	0
Stock based compensation	1	0	0
(Gain) loss on sale of mortgage-backed securities, net	(109)	23	(51)
Unrealized loss on investment securities measured at fair value through net income, net	6	5	32
Loss on derivative instruments and other securities, net	310	754	1,211
(Increase) decrease in other assets	34	(83)	55
Increase (decrease) in accounts payable and other accrued liabilities	46	5	(20)
Net cash provided by operating activities	1,352	1,428	1,622
Investing activities:
Purchases of mortgage-backed securities	(20,836)	(32,770)	(26,349)
Payments To Acquire Non- Agency Mortgage Backed Securities	(34)	(116)	0
Proceeds from sale of mortgage-backed securities	18,030	27,794	30,587
Principal collections on mortgage-backed securities	8,137	7,922	7,358
Purchases of credit risk transfer securities	(195)	0	0
Purchases of U.S. Treasury securities	(4,483)	(49,724)	(51,511)
Proceeds from sale of U.S. Treasury securities	10,393	48,354	56,068
Net proceeds from (payments on) reverse repurchase agreements	(6,003)	3,505	(3,337)
Net proceeds from (payments on) other derivative instruments	(1,399)	(300)	313
Purchases of REIT equity securities	0	(11)	(234)
Proceeds from sale of REIT equity securities	39	35	416
Purchase of AGNC Mortgage Management, LLC, net of cash acquired	(555)	0	0
(Increase) decrease in restricted cash and cash equivalents	1,244	(568)	(612)
Other investing cash flows, net	107	(28)	(350)
Net cash provided by investing activities	4,445	4,093	12,349
Financing activities:
Proceeds from repurchase arrangements	217,501	380,580	291,736
Payments on repurchase agreements	(221,434)	(389,122)	(304,973)
Proceeds from Federal Home Loan Bank advances	2,098	12,957	0
Payments on Federal Home Loan Bank advances	(2,814)	(9,204)	0
Payments on debt of consolidated variable interest entities	(135)	(155)	(158)
Proceeds from Issuance of Preferred Stock and Preference Stock	0	0	169
Payments for common stock repurchases	(116)	(285)	(74)
Cash dividends paid	(799)	(902)	(1,094)
Net cash used in financing activities	(5,699)	(6,131)	(14,394)
Net change in cash and cash equivalents	98	(610)	(423)
Cash and cash equivalents at beginning of period	1,110	1,720	2,143
Cash and cash equivalents at end of period	1,208	1,110	1,720
Income Taxes Paid	$ 0	$ 1	$ 3

Unaudited Interim Consolidated

Unaudited Interim Consolidated Financial Statements	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Unaudited Interim Consolidated Financial Statements	uarterly Results (Unaudited) The following is a presentation of the quarterly results of operations and comprehensive income for fiscal years 2016 and 2015 (in millions, except per share data). Quarter Ended March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 Interest income: Interest income $ 295 $ 318 $ 315 $ 393 Interest expense 99 101 96 98 Net interest income 196 217 219 295 Other gain (loss): Gain (loss) on sale of investment securities, net (2 ) 55 61 (5 ) Unrealized gain (loss) on investment securities measured at fair value through net income, net 11 — (6 ) (11 ) Gain (loss) on derivative instruments and other securities, net (944 ) (367 ) 248 753 Management fee income — — 4 4 Total other gain (loss), net (935 ) (312 ) 307 741 Expenses: Management fee expense 27 25 — — Compensation and benefits — — 9 10 Other operating expenses 6 15 6 7 Total expenses 33 40 15 17 Net income (loss) (772 ) (135 ) 511 1,019 Dividend on preferred stock 7 7 7 7 Net income (loss) available (attributable) to common shareholders $ (779 ) $ (142 ) $ 504 $ 1,012 Net income (loss) $ (772 ) $ (135 ) $ 511 $ 1,019 Other comprehensive income (loss): Unrealized gain (loss) on available-for-sale securities, net 765 370 (97 ) (1,408 ) Unrealized gain on derivative instruments, net 19 12 7 1 Other comprehensive income (loss) 784 382 (90 ) (1,407 ) Comprehensive income (loss) 12 247 421 (388 ) Dividend on preferred stock 7 7 7 7 Comprehensive income (loss) available (attributable) to common shareholders $ 5 $ 240 $ 414 $ (395 ) Weighted average number of common shares outstanding - basic and diluted 334.4 331.0 331.0 331.0 Net income (loss) per common share - basic and diluted $ (2.33 ) $ (0.43 ) $ 1.52 $ 3.06 Comprehensive income (loss) per common share - basic and diluted $ 0.01 $ 0.73 $ 1.25 $ (1.19 ) Dividends declared per common share $ 0.60 $ 0.60 $ 0.56 $ 0.54 Quarter Ended March 31, June 30, 2015 September 30, December 31, 2015 Interest income: Interest income $ 383 $ 414 $ 295 $ 374 Interest expense 86 81 77 86 Net interest income 297 333 218 288 Other gain (loss): Gain (loss) on sale of investment securities, net 36 (22 ) (39 ) 2 Unrealized gain (loss) on investment securities measured at fair value through net income, net 11 (7 ) 10 (9 ) Gain (loss) on derivative instruments and other securities, net (560 ) 244 (788 ) 340 Total other gain (loss), net (513 ) 215 (817 ) 333 Expenses: Management fees 30 29 29 28 General and administrative expenses 6 7 5 5 Total expenses 36 36 34 33 Net income (loss) (252 ) 512 (633 ) 588 Dividend on preferred stock 7 7 7 7 Net income (loss) available (attributable) to common shareholders $ (259 ) $ 505 $ (640 ) $ 581 Net income (loss) $ (252 ) $ 512 $ (633 ) $ 588 Other comprehensive income (loss): Unrealized gain (loss) on available-for-sale securities, net 391 (872 ) 467 (583 ) Unrealized gain on derivative instruments, net 29 26 24 22 Other comprehensive income (loss) 420 (846 ) 491 (561 ) Comprehensive income (loss) 168 (334 ) (142 ) 27 Dividend on preferred stock 7 7 7 7 Comprehensive income (loss) available (attributable) to common shareholders $ 161 $ (341 ) $ (149 ) $ 20 Weighted average number of common shares outstanding-basic and diluted 352.8 352.1 347.8 341.6 Net income (loss) per common share - basic and diluted $ (0.73 ) $ 1.43 $ (1.84 ) $ 1.70 Comprehensive income (loss) per common share - basic and diluted $ 0.46 $ (0.97 ) $ (0.43 ) $ 0.06 Dividends declared per common share $ 0.66 $ 0.62 $ 0.60 $ 0.60

Organization

Organization	12 Months Ended
	Dec. 31, 2016
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 ("IPO"). Our common stock is traded on The NASDAQ Global Select Market under the symbol "AGNC." We operate so as 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 net income. As long as we continue to qualify as a REIT, we will generally not be subject to U.S. federal or state corporate taxes on our taxable net income to the extent that we distribute our annual taxable net income to our stockholders on a timely basis. It is our intention to distribute 100% of our taxable net income, after application of available tax attributes, within the limits prescribed by the Internal Revenue Code, which may extend into the subsequent taxable year. We earn income primarily from investing in Agency residential mortgage-backed securities ("Agency RMBS") on a leveraged basis. These investments consist of residential pass-through mortgage securities for which the principal and interest payments are guaranteed by a U.S. Government-sponsored enterprise or a U.S. Government agency. We may also invest in other types of mortgage and mortgage-related securities, such as credit risk transfer ("CRT") securities and non-Agency residential mortgage-backed securities ("non-Agency RMBS") and commercial mortgage-backed securities ("CMBS"), where repayment of principal and interest is not guaranteed by a U.S. Government-sponsored enterprise or U.S. Government agency (see Note 2 for further details). Our principal objective is to provide our stockholders with attractive risk-adjusted returns through a combination of monthly dividends and net asset value (also referred to as "net book value," "NAV" and "stockholders' equity") accretion. We generate income from the interest earned on our investment assets, net of associated borrowing and hedging activities, and net realized gains and losses on our investments and hedging activities. We fund our investments primarily through borrowings structured as repurchase agreements. Prior to July 1, 2016, we were externally managed by AGNC Management, LLC, (formerly known as American Capital AGNC Management, LLC) (our "Manager"). On July 1, 2016, we completed the acquisition of all of the outstanding membership interests of AGNC Mortgage Management, LLC ("AMM," formerly known as American Capital Mortgage Management, LLC), the parent company of our Manager, from American Capital Asset Management, LLC ("ACAM"), a wholly owned portfolio company of American Capital, Ltd. ("ACAS"). AMM is also the parent company of MTGE Management, LLC ("MTGE Manager," formerly known as American Capital MTGE Management, LLC), the external manager of MTGE Investment Corp. ("MTGE," formerly known as American Capital Mortgage Investment Corp.). Following the closing of the acquisition of AMM, we became internally managed and are no longer affiliated with ACAS (see Notes 11and 12 for further details).

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
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. Earnings per Share Basic earnings per share ("EPS") is computed by dividing net income (loss) available (attributable) to common stockholders by the weighted average number of common shares outstanding during the period. Diluted EPS assumes the conversion, exercise or issuance of all potential common stock equivalents unless the effect is to reduce a loss or increase the income per share. Accumulated Other Comprehensive Income (Loss) Accounting Standards Codification ("ASC") Topic 220, Comprehensive Income , divides comprehensive income into net income and other comprehensive income (loss) ("OCI"), which includes unrealized gains and losses on securities classified as available-for-sale and unrealized gains and losses on derivative financial instruments that are designated and qualify for cash flow hedge accounting under ASC Topic 815, Derivatives and Hedging ("ASC 815"). During fiscal year 2011, we discontinued designating our derivative financial instruments, principally interest rate swaps, as cash flow hedges. For further information regarding our discontinuation of cash flow hedge accounting, see Derivatives Instruments below and Note 5. Cash and Cash Equivalents Cash and cash equivalents consist of unrestricted demand deposits and highly liquid investments with original maturities of three months or less. Cash and cash equivalents are carried at cost, which approximates fair value. Restricted Cash and Cash Equivalents Restricted cash and cash equivalents includes cash and cash equivalents pledged as collateral for clearing and executing trades, repurchase agreements and other borrowings, and interest rate swaps and other derivative instruments. Restricted cash and cash equivalents are carried at cost, which approximates fair value. Investment Securities We primarily invest in Agency RMBS. Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") for which the principal and interest payments are guaranteed by a U.S. Government-sponsored enterprise, such as the Federal National Mortgage Association ("Fannie Mae") and the Federal Home Loan Mortgage Corporation ("Freddie Mac"), or by a U.S. Government agency, such as the Government National Mortgage Association ("Ginnie Mae") (collectively referred to as "GSEs"). Interest-only and inverse interest-only securities (together referred to as "interest-only securities") represent the right to receive a specified proportion of the contractual interest flows of specific Agency CMO securities. Principal-only securities represent the right to receive the contractual principal flows of specific Agency CMO securities. CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third party market participants, that 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 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 are able to 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. REIT equity securities represent investments in the common stock of other publicly traded mortgage REITs that invest primarily in Agency RMBS. 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 for such securities pursuant to ASC Topic 825, Financial Instruments . We report securities classified as trading or available-for-sale or for which if we elected the fair value option at fair value, while securities classified as held-to-maturity are reported at amortized cost. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income (loss) ("OCI"). Unrealized gains and losses on securities classified as trading or for which we elected the fair value option are reflected in net income through other gain (loss) during the period in which they occur. We may sell any of our securities as part of our overall management of our investment portfolio. Accordingly, unless we elect the fair value option, we typically designate our investment securities as available-for-sale. Investments in REIT equity securities are designated as trading securities. 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. We have elected the fair value option to account for CRT securities, interest and principal-only securities and CMBS as this election simplifies the accounting for such securities. Effective January 1, 2017, we elected the fair value option for future purchases of all investment securities, including Agency RMBS and non-Agency MBS. In our view, this election will more appropriately reflect the result of our operations for a particular reporting period, as the fair value changes for these financial assets will be presented in a manner consistent with the presentation and timing of the fair value changes of our hedging instruments. We are not permitted to change the designation of available-for-sale securities acquired prior to January 1, 2017, accordingly, such securities will continue to be classified as available-for-sale securities until such time as we receive full repayment or we dispose of the security. We estimate the fair value of Agency RMBS, non-Agency MBS and CRT securities based on a market approach using "Level 2" inputs from third-party pricing services and non-binding dealer quotes derived from common market pricing methods. Such methods incorporate, but are not limited to, reported trades and executable bid and asked prices for similar securities, benchmark interest rate curves, such as the spread to the U.S. Treasury rate and interest rate swap curves, convexity, duration and the underlying characteristics of the particular security, including coupon, periodic and life caps, rate reset period, issuer, additional credit support and expected life of the security. We estimate the fair value of REIT equity securities based on a market approach using "Level 1" inputs based on quoted market prices. Refer to Note 7 for further discussion of fair value measurements. We evaluate our investments designated as available-for-sale for other-than-temporary impairment ("OTTI") on at least a quarterly basis. 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. However, with respect to the first condition, since the liquidity of the Agency securities market allows us to obtain competitive bids and execute on a sale transaction typically within a day of making the decision to sell a security, we generally do not make decisions to sell specific mortgage securities until shortly prior to initiating a sell order. In some instances, we may sell specific Agency securities by delivering the securities into existing short "to-be-announced" ("TBA") contracts. TBA market conventions require the identification of the specific securities to be delivered no later than 48 hours prior to settlement. If we settle a short TBA contract through the delivery of securities, we will generally identify the specific securities to be delivered within one to two days before the 48-hour deadline. 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. However, in evaluating if the third condition exists, our investments in Agency securities typically would not have a credit component since the principal and interest are guaranteed by a GSE and, therefore, any unrealized loss is not the result of a credit loss. In addition, since unrealized gains and losses for securities designated as available-for-sale are recognized in OCI, any impairment loss for non-credit components is already recognized in OCI. We did not recognize any OTTI charges on our investment securities for fiscal years 2016 , 2015 or 2014. 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 estimates prepayment speeds using models that incorporate the forward yield curve, current mortgage rates and 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 prepayment speeds estimated by the third-party service and, based on our judgment, we may make adjustments to its estimates. Actual and anticipated prepayment experience is reviewed quarterly and effective yields are recalculated when differences arise between (i) our previously estimated future prepayments and (ii) the actual prepayments to date plus our currently estimated future prepayments. If the actual and estimated future prepayment experience differs from our prior estimate of prepayments, we are required to record an adjustment in the current period to the amortization or accretion of premiums and discounts for the cumulative difference in the effective yield 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 about interest rates, prepayment rates, the timing and amount of credit losses, and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment as adjusted for credit impairment, 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 ("ASC 860"), we account for repurchase transactions as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest, as specified in the respective transactions. Our repurchase agreements typically have maturities of less than one year, but may extend up to five years or more. Interest rates under our repurchase agreements generally correspond to one, three or six month LIBOR 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. Federal Home Loan Bank Advances Federal Home Loan Bank ("FHLB") advances are secured loans from the FHLB of Des Moines used to finance the acquisitions of investment securities. We account for FHLB advances as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest, as specified in the respective transactions. In April 2015, our wholly-owned captive insurance subsidiary, Old Georgetown Insurance Co., LLC ("OGI"), was approved as a member of the FHLB of Des Moines. The FHLBs provide a variety of products and services to their members, including short and long-term secured loans. In January 2016, the Federal Housing Finance Agency released its final rule on changes to regulations concerning FHLB membership criteria. The final rule terminated OGI's FHLB membership and required repayment of all advances at the earlier of their contractual maturity dates or a one year period after the effective date of the final rule that concluded in February 2017. Interest rates under our FHLB advances generally correspond to the FHLB's Member Option Variable Rate or to one or three month LIBOR plus or minus a fixed spread. The fair value of our FHLB advances 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 from time to time borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivatives 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. Our reverse repurchase agreements generally mature daily. The fair value of our reverse repurchase agreements is assumed to equal cost as the interest rates are generally reset daily. 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 risk. 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 principal instruments that we use are interest rate swaps and options to enter into interest rate swaps ("swaptions"). We also utilize U.S. Treasury securities and U.S. Treasury futures contracts, primarily through short sales, and forward contracts for the purchase or sale of Agency RMBS securities on a generic pool basis in the "to-be-announced" market ("TBA securities") and on a specified pool basis. We may also purchase or write put or call options on TBA securities and utilize other types of derivative instruments to hedge a portion of our risk. We also enter into TBA contracts as a means of investing in and financing Agency securities (thereby increasing our "at risk" leverage) or as a means of disposing of or reducing our exposure to Agency securities (thereby reducing our "at risk" leverage). Under TBA contracts, we agree to purchase or sell, for future delivery, Agency securities with certain principal and interest terms and certain types of collateral, but the particular Agency securities to be delivered are not identified until shortly before the TBA settlement date. We may also choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting short or long position (referred to as a "pair off"), net settling the paired off positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date. This transaction is commonly referred to as a "dollar roll." The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to Agency securities for settlement in the current month. This difference (or discount) is referred to as the "price drop." The price drop is the economic equivalent of net interest carry income on the underlying Agency securities over the roll period (interest income less implied financing cost) and is commonly referred to as "dollar roll income/loss." Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. 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. 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 in the event that the counterparties to these instruments fail to perform their obligations under the contracts. We attempt to minimize this risk by limiting our counterparties to major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Discontinuation of hedge accounting for interest rate swap agreements Prior to fiscal year 2011, we entered into interest rate swap agreements typically with the intention of qualifying for hedge accounting under ASC 815. However, during fiscal year 2011, we elected to discontinue hedge accounting for our interest rate swaps. Upon discontinuation of hedge accounting, the net deferred loss related to our de-designated interest rate swaps remained in accumulated OCI and has been reclassified from accumulated OCI into interest expense on a straight-line basis over the remaining term of each interest rate swap through December 2016. Interest rate swap agreements We use interest rate swaps to hedge the variable cash flows associated with borrowings made under our repurchase agreement facilities. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate based on one, three or six-month LIBOR ("payer swaps") with terms up to 20 years. The floating rate we receive under our swap agreements has the effect of offsetting the repricing characteristics of our repurchase agreements and cash flows on such liabilities. Our swap agreements are privately negotiated in the over−the−counter ("OTC") market. Swap agreements entered into subsequent to May 2013 are centrally cleared through a registered commodities exchange ("centrally cleared swaps"). We estimate the fair value of our centrally cleared interest rate swaps using the daily settlement price determined by the respective exchange. Centrally cleared swaps are valued by the exchange using a pricing model that references the underlying rates including the overnight index swap rate and LIBOR forward rate to produce the daily settlement price. We estimate the fair value of our "non-centrally cleared" swaps using a combination of inputs from counterparty and third-party pricing models to estimate the net present value of the future cash flows using the forward interest rate yield curve in effect as of the end of the measurement period. We also incorporate 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 consider 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 generally 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 swaption agreements typically provide us the option to enter into a pay-fixed rate interest rate swap, which we refer as "payer swaptions." We may also enter into swaption agreements that provide us the option to enter into a receive-fixed interest rate swap, which we refer to as "receiver swaptions." The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. The premium is valued at an amount equal to the fair value of the swaption that would have the effect of closing the position adjusted for nonperformance risk, if any. The difference between the premium 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 received and the premium paid. Our interest rate swaption agreements are privately negotiated in the OTC market and are not subject to central clearing. 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. TBA securities A TBA security is a forward contract for the purchase ("long position") or sale ("short position") of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS delivered into the contract upon the settlement date, published each month by the Securities Industry and Financial Markets Association, are not known at the time of the transaction. We may enter into TBA contracts as a means of hedging against short-term changes in interest rates. We may also enter into TBA contracts as a means of acquiring or disposing of Agency securities and utilize TBA dollar roll transactions to finance Agency RMBS purchases. 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 take physical delivery of the Agency security upon settlement of the contract. We account for TBA dollar roll transactions as a series of derivative transactions. Gains, losses and dollar roll income associated with our TBA contracts and dollar roll transactions are recognized in our consolidated statements of comprehensive income in gain (loss) on derivative instruments and other securities, net. We estimate the fair value of TBA securities based on similar methods used to value our Agency RMBS securities. U.S. Treasury securities We purchase and sell short U.S. Treasury securities and U.S. Treasury futures contracts to help mitigate the potential impact of changes in interest rates on the performance of our portfolio. We borrow securities to cover short sales of U.S. Treasury securities under reverse repurchase agreements. 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 borrowed securities as of the reporting date. Gains and losses associated with purchases and short sales of 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. 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. Further, ASC 810 requires a qualitative assessment to determine the primary beneficiary of a VIE and ongoing assessments of whether an enterprise is the primary beneficiary of a VIE as well as additional disclosures for entities that have variable interests in VIEs. We have entered into transactions involving CMO trusts, which are VIEs. We will consolidate a CMO trust if we are the CMO trust's primary beneficiary; that is, if we have a variable interest that provides us with a controlling financial interest in the CMO trust. An entity is deemed to have a controlling financial interest if the entity has the power to direct the activities of a VIE that most significantly impact the VIE's economic performance and the obligation to absorb losses of or right to receive benefits from the VIE that could potentially be significant to the VIE. As part of the qualitative assessment in determining if we have a controlling financial interest, we evaluate whether we control the selection of financial assets transferred to the CMO trust. For each of our consolidated CMO trusts we controlled the selection of the Agency RMBS transferred from our investment portfolio to an investment bank in exchange for cash proceeds and at the same time entered into a commitment with the investment bank to purchase to-be-issued securities collateralized by the Agency RMBS transferred, which resulted in our consolidation of the CMO trusts. Agency RMBS transferred to consolidated VIEs are reported on our consolidated balance sheets in Agency securities transferred to consolidated VIEs, at fair value and can only be used to settle the obligations of each respective VIE. We elected the option to account for the consolidated debt at fair value, with changes in fair value reflected in earnings during the period in which they occur, because 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 transferred to consolidated VIEs, less the fair value of our retained interests, which are measured on a market approach using "Level 2" inputs from third-party pricing services and dealer quotes. The fair value of the Agency RMBS transferred to the consolidated VIEs and the fair value of our retained interests are based on more observable inputs than inputs used to independently determine the value of our consolidated debt. Loss Contingencies We evaluate the existence of any pending or threatened litigation or other potential claims against the Company in accordance with ASC Topic 450, Contingencies, which requires that we assess the likelihood and range of potential outcomes of any such matters. We are the defendant in two stockholder derivative lawsuits alleging that certain of our current and former directors and officers breached fiduciary duties and wasted corporate assets in connection with past renewals of the management agreement with our former external Manager and the internalization of our management, which occurred on July 1, 2016. Although the outcomes of these cases cannot be predicted with certainty, we do not believe that these cases have merit or will result in a material liability and, as of December 31, 2016, we did not accrue a loss contingency related to these matters. Income Taxes We elected to be taxed as a REIT under the provisions of the Internal Revenue Code and the corresponding provisions of state law, commencing with our initial tax year ended December 31, 2008. In order to continue to qualify as a REIT, we must annually distribute, in a timely manner to our stockholders, at least 90% of our taxable ordinary income, amongst other conditions. A REIT is generally not subject to U.S. federal and state corporate income tax on its earnings to the extent that it distributes its annual taxable net income to its stockholders and as long as certain asset, income and stock ownership tests are met. We operate in a manner that will allow us to be taxed as a REIT. As permitted by the Internal Revenue Code, a REIT can designate dividends paid in the subsequent year as dividends of the current year if those dividends are both declared by the extended due date of the REIT's federal income tax return and paid to stockholders by the last day of the subsequent year; however, we may still be subject to a non-deductible 4% excise tax if the actual amount distributed to our stockholders in a calendar year is less than the minimum amount specified under federal tax laws. We have a wholly-owned subsidiary for which we elected to treat as taxable REIT subsidiary. As such it is subject to federal and stat

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Investment Securities	3 years and ≤ 5 years 13,534 13,449 3.26% 2.40% 17,497 17,343 3.27% 2.40% > 5 years and ≤10 years 30,226 30,713 3.65% 2.86% 34,206 34,391 3.67% 2.93% > 10 years 1,843 1,842 3.02% 3.07% 250 250 3.56% 3.08% Total $ 46,017 $ 46,414 3.52% 2.73% $ 52,120 $ 52,147 3.54% 2.75% The following table presents the gross unrealized loss and fair values of our available-for-sale securities by length of time that such securities have been in a continuous unrealized loss position as of December 31, 2016 and 2015 (in millions): Unrealized Loss Position For Less than 12 Months 12 Months or More Total Securities Classified as Available-for-Sale Estimated Fair Value Unrealized Loss Estimated Fair Value Unrealized Loss Estimated Fair Value Unrealized Loss December 31, 2016 $ 28,397 $ (554 ) $ 1,719 $ (68 ) $ 30,116 $ (622 ) December 31, 2015 $ 24,035 $ (200 ) $ 6,793 $ (195 ) $ 30,828 $ (395 ) We did not recognize any OTTI charges on our investment securities for fiscal year s 2016 and 2015 . As of the end of each respective reporting period, a decision had not been made to sell any of our 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. The unrealized losses on our securities were not due to credit losses given the GSE guarantees, but rather were due to changes in interest rates and prepayment expectations. However, as we continue to actively manage our portfolio, we may recognize additional realized losses on our investment securities upon selecting specific securities to sell. Gains and Losses on Sale of Investment Securities The following table is a summary of our net gain (loss) from the sale of securities classified as available-for-sale for fiscal years 2016 , 2015 and 2014 (in millions). Please refer to Note 8 for a summary of changes in accumulated OCI for the same periods . Fiscal Year Securities Classified as Available-for-Sale 2016 2015 2014 RMBS sold, at cost $ (17,907 ) $ (27,578 ) $ (30,123 ) Proceeds from RMBS sold 1 18,016 27,555 30,174 Net gain (loss) on sale of RMBS $ 109 $ (23 ) $ 51 Gross gain on sale of RMBS $ 123 $ 98 $ 172 Gross loss on sale of RMBS (14 ) (121 ) (121 ) Net gain (loss) on sale of RMBS $ 109 $ (23 ) $ 51 ________________________ 1. Proceeds include cash received during the period, plus receivable for RMBS sold during the period as of period end. Securitizations and Variable Interest Entities As of December 31, 2016 and 2015 , we held investments in CMO trusts, which are variable interest entities ("VIEs"). We have consolidated certain of these CMO trusts in our consolidated financial statements where we have determined we are the primary beneficiary of the trusts. All of our CMO securities are 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 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. In connection with our consolidated CMO trusts, we recognized Agency securities with a total fair value of $0.8 billion and $1.0 billion as of December 31, 2016 and 2015 , respectively, and debt with a total fair value of $460 million and $595 million , respectively, in our accompanying consolidated balance sheets. As of December 31, 2016 and 2015 , the Agency securities had an aggregate unpaid principal balance of $0.8 billion and $1.0 billion , respectively, and the debt had an aggregate unpaid principal balance of $452 million and $587 million , respectively. We re-measure our consolidated debt at fair value through earnings in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. For fiscal years 2016 , 2015 and 2014, we recorded a loss of $3 million , a gain of $16 million and a loss of $10 million , respectively, associated with our consolidated debt. Our involvement with the consolidated trusts is limited to the Agency securities transferred by us upon the formation of the trusts and the CMO securities subsequently held by us. There are no arrangements that could require us to provide financial support to the trusts. As of December 31, 2016 and 2015 , the fair value of our CMO securities and interest and principal-only securities was $1.1 billion and $1.3 billion , respectively, excluding the consolidated CMO trusts discussed above, or $1.5 billion and $1.8 billion , respectively, including the net asset value of our consolidated CMO trusts. Our maximum exposure to loss related to our CMO securities and interest and principal-only securities, including our consolidated CMO trusts, was $182 million and $238 million as of December 31, 2016 and 2015 , respectively." id="sjs-B4">Investment Securities As of December 31, 2016 and 2015 , our investment portfolio consisted of $46.5 billion and $52.5 billion of investment securities, at fair value, respectively, summarized in the tables below, and $11.2 billion and $7.4 billion net TBA securities, at fair value, respectively. Our TBA position is reported at its net carrying value of $(147) million and $14 million as of December 31, 2016 and 2015 , 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 (see Note 5 for further details of our net TBA position as of December 31, 2016 and 2015 ). As of December 31, 2016 and 2015 , our investment securities had a net unamortized premium balance of $2.1 billion and $2.3 billion , respectively, including interest and principal-only securities. The following tables summarize our investment securities as of December 31, 2016 and 2015 (dollars in millions): December 31, 2016 Investment Securities Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Agency RMBS: Fixed rate $ 45,145 $ 210 $ (619 ) $ 44,736 Adjustable rate 371 8 — 379 CMO 796 7 (2 ) 801 Interest-only and principal-only strips 268 31 (4 ) 295 Total Agency RMBS 46,580 256 (625 ) 46,211 Non-Agency RMBS 102 — (1 ) 101 CMBS 23 — — 23 CRT securities 161 3 — 164 Total investment securities $ 46,866 $ 259 $ (626 ) $ 46,499 December 31, 2015 Investments Securities Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Agency RMBS: Fixed rate $ 50,576 $ 339 $ (393 ) $ 50,522 Adjustable rate 484 11 — 495 CMO 973 18 (1 ) 990 Interest-only and principal-only strips 317 39 (3 ) 353 Total Agency RMBS 52,350 407 (397 ) 52,360 Non-Agency RMBS 114 — (1 ) 113 Total investment securities $ 52,464 $ 407 $ (398 ) $ 52,473 December 31, 2016 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 34,244 $ 10,008 $ 44 $ 101 $ — $ — $ 44,397 Unamortized discount (43 ) (3 ) — — — — (46 ) Unamortized premium 1,518 544 — 1 — — 2,063 Amortized cost 35,719 10,549 44 102 — — 46,414 Gross unrealized gains 176 48 1 — — — 225 Gross unrealized losses (442 ) (179 ) — (1 ) — — (622 ) Total available-for-sale securities, at fair value 35,453 10,418 45 101 — — 46,017 Securities remeasured at fair value through earnings: Par value 1 171 — — — 24 157 352 Unamortized discount (35 ) — — — (1 ) — (36 ) Unamortized premium 118 14 — — — 4 136 Amortized cost 254 14 — — 23 161 452 Gross unrealized gains 28 3 — — — 3 34 Gross unrealized losses (3 ) (1 ) — — — — (4 ) Total securities remeasured at fair value through earnings 279 16 — — 23 164 482 Total securities, at fair value $ 35,732 $ 10,434 $ 45 $ 101 $ 23 $ 164 $ 46,499 Weighted average coupon as of December 31, 2016 3.59 % 3.67 % 2.75 % 3.42 % 6.55 % 5.25 % 3.61 % Weighted average yield as of December 31, 2016 2 2.77 % 2.72 % 2.00 % 3.27 % 7.54 % 6.28 % 2.77 % ________________________ 1. Par value amount excludes the underlying unamortized principal balance ("UPB") of interest-only securities of $0.9 billion as of December 31, 2016 . 2. Incorporates a weighted average future constant prepayment rate assumption of 8% based on forward rates as of December 31, 2016 . December 31, 2015 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS Total Available-for-sale securities: Par value $ 39,205 $ 10,575 $ 62 $ 113 $ 49,955 Unamortized discount (32 ) (4 ) — — (36 ) Unamortized premium 1,707 519 1 1 2,228 Amortized cost 40,880 11,090 63 114 52,147 Gross unrealized gains 286 80 2 — 368 Gross unrealized losses (283 ) (111 ) — (1 ) (395 ) Total available-for-sale securities, at fair value 40,883 11,059 65 113 52,120 Securities remeasured at fair value through earnings: Par value 1 208 — — — 208 Unamortized discount (42 ) — — — (42 ) Unamortized premium 132 19 — — 151 Amortized cost 298 19 — — 317 Gross unrealized gains 35 4 — — 39 Gross unrealized losses (2 ) (1 ) — — (3 ) Total securities remeasured at fair value through earnings 331 22 — — 353 Total securities, at fair value $ 41,214 $ 11,081 $ 65 $ 113 $ 52,473 Weighted average coupon as of December 31, 2015 3.62 % 3.69 % 3.18 % 3.50 % 3.63 % Weighted average yield as of December 31, 2015 2 2.79 % 2.77 % 1.97 % 3.33 % 2.78 % ________________________ 1. Par value amount excludes the UPB of interest-only securities of $1.0 billion as of December 31, 2015 . 2. Incorporates a weighted average future constant prepayment rate assumption of 8% based on forward rates as of December 31, 2015 . As of December 31, 2016 and 2015, our investments in non-Agency securities had the following credit ratings: December 31, 2016 December 31, 2015 Non-Agency Security Credit Ratings 1 CRT RMBS CMBS CRT RMBS CMBS AAA $ — $ 99 $ — $ — $ 113 $ — BBB — — 23 — — — B 164 2 — — — — Total $ 164 $ 101 $ 23 $ — $ 113 $ — ________________________ 1. Represents the lowest of Standard and Poor's ("S&P"), Moody's and Fitch credit ratings, stated in terms of the S&P equivalent rating as of each date. Our CRT securities reference the performance of loans that have been guaranteed by Fannie Mae or Freddie Mac, subject to their underwriting standards. As of December 31, 2016 , our CRT securities had floating rate coupons ranging from 4.6% to 7.1% , with weighted average coupons of underlying collateral ranging from 4.0% to 4.2% . The loans underlying our CRT securities were originated between 2015 and 2016 . The actual maturities of our investment securities are generally shorter than their stated contractual maturities. Actual maturities are affected by the contractual lives of the underlying mortgages, periodic contractual principal payments and principal prepayments. As of December 31, 2016 and 2015 , the weighted average expected constant prepayment rate ("CPR") over the remaining life of our aggregate investment portfolio was 8% . Our estimates differ materially for different types of securities and thus individual holdings have a wide range of projected CPRs. The following table summarizes our investments classified as available-for-sale as of December 31, 2016 and 2015 according to their estimated weighted average life classification (dollars in millions): December 31, 2016 December 31, 2015 Estimated Weighted Average Life of Securities Classified as Available-for-Sale Fair Value Amortized Cost Weighted Average Coupon Weighted Average Yield Fair Value Amortized Cost Weighted Average Coupon Weighted Average Yield ≥ 1 year and ≤ 3 years $ 414 $ 410 3.99% 2.52% $ 167 $ 163 4.02% 2.66% > 3 years and ≤ 5 years 13,534 13,449 3.26% 2.40% 17,497 17,343 3.27% 2.40% > 5 years and ≤10 years 30,226 30,713 3.65% 2.86% 34,206 34,391 3.67% 2.93% > 10 years 1,843 1,842 3.02% 3.07% 250 250 3.56% 3.08% Total $ 46,017 $ 46,414 3.52% 2.73% $ 52,120 $ 52,147 3.54% 2.75% The following table presents the gross unrealized loss and fair values of our available-for-sale securities by length of time that such securities have been in a continuous unrealized loss position as of December 31, 2016 and 2015 (in millions): Unrealized Loss Position For Less than 12 Months 12 Months or More Total Securities Classified as Available-for-Sale Estimated Fair Value Unrealized Loss Estimated Fair Value Unrealized Loss Estimated Fair Value Unrealized Loss December 31, 2016 $ 28,397 $ (554 ) $ 1,719 $ (68 ) $ 30,116 $ (622 ) December 31, 2015 $ 24,035 $ (200 ) $ 6,793 $ (195 ) $ 30,828 $ (395 ) We did not recognize any OTTI charges on our investment securities for fiscal year s 2016 and 2015 . As of the end of each respective reporting period, a decision had not been made to sell any of our 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. The unrealized losses on our securities were not due to credit losses given the GSE guarantees, but rather were due to changes in interest rates and prepayment expectations. However, as we continue to actively manage our portfolio, we may recognize additional realized losses on our investment securities upon selecting specific securities to sell. Gains and Losses on Sale of Investment Securities The following table is a summary of our net gain (loss) from the sale of securities classified as available-for-sale for fiscal years 2016 , 2015 and 2014 (in millions). Please refer to Note 8 for a summary of changes in accumulated OCI for the same periods . Fiscal Year Securities Classified as Available-for-Sale 2016 2015 2014 RMBS sold, at cost $ (17,907 ) $ (27,578 ) $ (30,123 ) Proceeds from RMBS sold 1 18,016 27,555 30,174 Net gain (loss) on sale of RMBS $ 109 $ (23 ) $ 51 Gross gain on sale of RMBS $ 123 $ 98 $ 172 Gross loss on sale of RMBS (14 ) (121 ) (121 ) Net gain (loss) on sale of RMBS $ 109 $ (23 ) $ 51 ________________________ 1. Proceeds include cash received during the period, plus receivable for RMBS sold during the period as of period end. Securitizations and Variable Interest Entities As of December 31, 2016 and 2015 , we held investments in CMO trusts, which are variable interest entities ("VIEs"). We have consolidated certain of these CMO trusts in our consolidated financial statements where we have determined we are the primary beneficiary of the trusts. All of our CMO securities are 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 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. In connection with our consolidated CMO trusts, we recognized Agency securities with a total fair value of $0.8 billion and $1.0 billion as of December 31, 2016 and 2015 , respectively, and debt with a total fair value of $460 million and $595 million , respectively, in our accompanying consolidated balance sheets. As of December 31, 2016 and 2015 , the Agency securities had an aggregate unpaid principal balance of $0.8 billion and $1.0 billion , respectively, and the debt had an aggregate unpaid principal balance of $452 million and $587 million , respectively. We re-measure our consolidated debt at fair value through earnings in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. For fiscal years 2016 , 2015 and 2014, we recorded a loss of $3 million , a gain of $16 million and a loss of $10 million , respectively, associated with our consolidated debt. Our involvement with the consolidated trusts is limited to the Agency securities transferred by us upon the formation of the trusts and the CMO securities subsequently held by us. There are no arrangements that could require us to provide financial support to the trusts. As of December 31, 2016 and 2015 , the fair value of our CMO securities and interest and principal-only securities was $1.1 billion and $1.3 billion , respectively, excluding the consolidated CMO trusts discussed above, or $1.5 billion and $1.8 billion , respectively, including the net asset value of our consolidated CMO trusts. Our maximum exposure to loss related to our CMO securities and interest and principal-only securities, including our consolidated CMO trusts, was $182 million and $238 million as of December 31, 2016 and 2015 , respectively.

Repurchase Agreements And Other

Repurchase Agreements And Other Debt	12 Months Ended
	Dec. 31, 2016
Disclosure of Repurchase Agreements [Abstract]
Repurchase Agreements And Other Debt	1 to ≤ 3 months 10,011 0.93 % 55 14,283 0.64 % 58 > 3 to ≤ 6 months 2,030 1.02 % 136 3,154 0.61 % 121 > 6 to ≤ 9 months 1,270 0.98 % 214 589 0.65 % 199 > 9 to ≤ 12 months 1,566 1.08 % 299 1,201 0.65 % 307 > 12 to ≤ 24 months 1,203 1.28 % 538 1,473 0.73 % 600 > 24 to ≤ 36 months 1,300 1.36 % 865 650 0.81 % 901 > 36 to ≤ 48 months 2,200 1.32 % 1,168 1,300 0.86 % 1,231 > 48 to < 60 months 625 1.38 % 1,506 1,500 0.76 % 1,477 Total Agency repo 37,686 0.98 % 187 41,729 0.61 % 173 U.S. Treasury repo: 1 day — — % — 25 — % 1 > 1 day to ≤ 1 month 172 (0.30 )% 17 — — % — Total $ 37,858 0.98 % 186 $ 41,754 0.61 % 173 Federal Home Loan Bank Advances On January 12, 2016, the Federal Housing Finance Agency ("FHFA") released its final rule on FHLB membership, which terminated of our wholly-owned captive insurance subsidiary's FHLB membership and required repayment of all FHLB advances at the earlier of their contractual maturity or a one year period that concluded in February 2017. As of December 31, 2016 and 2015 , we had $3.0 billion and $3.8 billion , respectively, of outstanding secured FHLB advances, with a weighted average borrowing rate of 0.73% and 0.53% , respectively, and a weighted average remaining term to maturity of 28 and 141 days, respectively, consisting of 30 day and longer-term floating rate advances: December 31, 2016 December 31, 2015 Remaining Maturity FHLB Advances Weighted Weighted FHLB Advances Weighted Weighted ≤ 1 month $ 1,353 0.67 % 7 $ 1,952 0.47 % 14 > 1 to ≤ 3 months 1,684 0.77 % 44 681 0.60 % 84 13 months — — % — 1,120 0.58 % 397 Total FHLB advances $ 3,037 0.73 % 28 $ 3,753 0.53 % 141 Debt of Consolidated Variable Interest Entities As of December 31, 2016 and 2015 , debt of consolidated VIEs, at fair value, was $460 million and $595 million , respectively, and had a weighted average interest rate of LIBOR plus 36 and 34 basis points, respectively, and a principal balance of $452 million and $587 million , respectively. The actual maturities of our debt of consolidated VIEs are generally shorter than the stated contractual maturities. The actual maturities are affected by the contractual lives of the underlying Agency RMBS securitizing the debt of our consolidated VIEs and periodic principal prepayments of such underlying securities. The estimated weighted average life of the debt of our consolidated VIEs as of December 31, 2016 and 2015 was 5.8 and 4.9 years, respectively." id="sjs-B4">Repurchase Agreements and Other Secured Borrowings We pledge certain of our securities as collateral under our repurchase agreements with financial institutions and under our secured borrowing facility with the Federal Home Loan Bank ("FHLB") of Des Moines. Interest rates on our borrowings are generally based on LIBOR plus or minus a margin and 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, 2016 , we had met all margin call requirements. For additional information regarding our pledged assets, please refer to Note 6 . Repurchase Agreements As of December 31, 2016 and 2015 , we had $37.9 billion and $41.8 billion , respectively, of repurchase agreements outstanding. 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 90 days have floating interest rates based on an index plus or minus a fixed spread. Substantially all of our repurchase agreements were used to fund purchases of Agency securities ("Agency repo"). The remainder of our repurchase agreements were used to fund temporary holdings of U.S. Treasury securities ("U.S. Treasury repo"). The following table summarizes our borrowings under repurchase agreements by their remaining maturities as of December 31, 2016 and 2015 (dollars in millions): December 31, 2016 December 31, 2015 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 $ 17,481 0.90 % 11 $ 17,579 0.54 % 14 > 1 to ≤ 3 months 10,011 0.93 % 55 14,283 0.64 % 58 > 3 to ≤ 6 months 2,030 1.02 % 136 3,154 0.61 % 121 > 6 to ≤ 9 months 1,270 0.98 % 214 589 0.65 % 199 > 9 to ≤ 12 months 1,566 1.08 % 299 1,201 0.65 % 307 > 12 to ≤ 24 months 1,203 1.28 % 538 1,473 0.73 % 600 > 24 to ≤ 36 months 1,300 1.36 % 865 650 0.81 % 901 > 36 to ≤ 48 months 2,200 1.32 % 1,168 1,300 0.86 % 1,231 > 48 to < 60 months 625 1.38 % 1,506 1,500 0.76 % 1,477 Total Agency repo 37,686 0.98 % 187 41,729 0.61 % 173 U.S. Treasury repo: 1 day — — % — 25 — % 1 > 1 day to ≤ 1 month 172 (0.30 )% 17 — — % — Total $ 37,858 0.98 % 186 $ 41,754 0.61 % 173 Federal Home Loan Bank Advances On January 12, 2016, the Federal Housing Finance Agency ("FHFA") released its final rule on FHLB membership, which terminated of our wholly-owned captive insurance subsidiary's FHLB membership and required repayment of all FHLB advances at the earlier of their contractual maturity or a one year period that concluded in February 2017. As of December 31, 2016 and 2015 , we had $3.0 billion and $3.8 billion , respectively, of outstanding secured FHLB advances, with a weighted average borrowing rate of 0.73% and 0.53% , respectively, and a weighted average remaining term to maturity of 28 and 141 days, respectively, consisting of 30 day and longer-term floating rate advances: December 31, 2016 December 31, 2015 Remaining Maturity FHLB Advances Weighted Weighted FHLB Advances Weighted Weighted ≤ 1 month $ 1,353 0.67 % 7 $ 1,952 0.47 % 14 > 1 to ≤ 3 months 1,684 0.77 % 44 681 0.60 % 84 13 months — — % — 1,120 0.58 % 397 Total FHLB advances $ 3,037 0.73 % 28 $ 3,753 0.53 % 141 Debt of Consolidated Variable Interest Entities As of December 31, 2016 and 2015 , debt of consolidated VIEs, at fair value, was $460 million and $595 million , respectively, and had a weighted average interest rate of LIBOR plus 36 and 34 basis points, respectively, and a principal balance of $452 million and $587 million , respectively. The actual maturities of our debt of consolidated VIEs are generally shorter than the stated contractual maturities. The actual maturities are affected by the contractual lives of the underlying Agency RMBS securitizing the debt of our consolidated VIEs and periodic principal prepayments of such underlying securities. The estimated weighted average life of the debt of our consolidated VIEs as of December 31, 2016 and 2015 was 5.8 and 4.9 years, respectively.

Derivative and Other Hedging In

Derivative and Other Hedging Instruments	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative and Other Hedging Instruments	3 to ≤ 5 years 7,450 1.62% 0.91% 44 4.0 9,950 2.03% 0.40% (203 ) 4.0 > 5 to ≤ 7 years 4,725 1.89% 0.91% 28 5.9 7,175 2.47% 0.44% (230 ) 6.1 > 7 to ≤ 10 years 3,325 1.90% 0.91% 114 9.2 7,450 2.57% 0.39% (342 ) 8.3 > 10 years 1,900 2.64% 0.91% (9 ) 13.8 1,175 3.20% 0.39% (91 ) 14.7 Total $ 37,175 1.48% 0.92% $ 216 3.9 $ 40,525 1.89% 0.40% $ (889 ) 4.6 ________________________ 1. As of December 31, 2016 and 2015 , notional amount includes forward starting swaps of $0.6 billion and $4.5 billion , respectively, with an average forward start date of 1.2 and 0.7 years, respectively, and an average maturity of 10.7 and 5.5 years, respectively. 2. Average fixed pay rate includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.46% and 1.75% as of December 31, 2016 and 2015 , respectively. 3. Average receive rate excludes forward starting swaps. The following tables summarize our interest rate payer swaption agreements, U.S. Treasury securities and U.S. Treasury futures outstanding as of December 31, 2016 and 2015 (dollars in millions): Payer Swaptions Option Underlying Payer Swap Years to Expiration Cost Fair Value Average Months to Expiration Notional Amount Average Fixed Pay Rate Average Receive Rate (LIBOR) Average Term (Years) December 31, 2016 Total ≤ 1 year $ 52 $ 22 6 $ 1,200 3.06% 3M 8.3 December 31, 2015 Total ≤ 1 year $ 74 $ 17 4 $ 2,150 3.51% 3M 7.0 U.S. Treasury Securities December 31, 2016 December 31, 2015 Maturity Face Amount Net Long / (Short) Cost Basis Net Fair Value Face Amount Net Long / (Short) Cost Basis Net Fair Value 5 years $ (400 ) $ (404 ) $ (392 ) $ (250 ) $ (249 ) $ (249 ) 7 years (3,056 ) (3,041 ) (2,930 ) (354 ) (353 ) (352 ) 10 years (4,416 ) (4,236 ) (4,132 ) (1,085 ) (1,078 ) (1,070 ) Total U.S. Treasury securities, net $ (7,872 ) $ (7,681 ) $ (7,454 ) $ (1,689 ) $ (1,680 ) $ (1,671 ) U.S. Treasury Futures December 31, 2016 December 31, 2015 Maturity Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 5 years $ (730 ) $ (862 ) $ (859 ) $ 3 $ (730 ) $ (866 ) $ (864 ) $ 2 10 years (1,080 ) (1,347 ) (1,342 ) 5 (1,130 ) (1,424 ) (1,422 ) 2 Total U.S. Treasury futures $ (1,810 ) $ (2,209 ) $ (2,201 ) $ 8 $ (1,860 ) $ (2,290 ) $ (2,286 ) $ 4 _____________________ 1. U.S. Treasury futures notional amount represents the par value (or principal balance) of the underlying U.S. Treasury security. 2. U.S. Treasury futures cost basis represents the forward price to be paid/(received) for the underlying U.S. Treasury security. 3. U.S. Treasury futures market value represents the current market value of U.S. Treasury futures as of period-end. 4. Net carrying value represents the difference between the fair value and the cost basis of U.S. Treasury futures as of period-end and is reported in derivative assets/(liabilities), at fair value in our consolidated balance sheets. The following tables summarize our TBA securities as of December 31, 2016 and 2015 (in millions): December 31, 2016 December 31, 2015 TBA Securities by Coupon Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 15-Year TBA securities: 2.5% $ 1,853 $ 1,870 $ 1,856 $ (14 ) $ (80 ) $ (81 ) $ (80 ) $ 1 3.0% 292 302 300 (2 ) 225 233 232 (1 ) 3.5% 15 16 16 — 136 143 142 (1 ) Total 15-Year TBA securities 2,160 2,188 2,172 (16 ) 281 295 294 (1 ) 30-Year TBA securities: 3.0% 3,027 3,114 3,007 (107 ) 3,914 3,911 3,916 5 3.5% 1,209 1,251 1,236 (15 ) 1,497 1,536 1,539 3 4.0% 4,530 4,769 4,760 (9 ) 1,575 1,658 1,665 7 4.5% (10 ) (10 ) (10 ) — 28 30 30 — Total 30-Year TBA securities, net 8,756 9,124 8,993 (131 ) 7,014 7,135 7,150 15 Total TBA securities, net $ 10,916 $ 11,312 $ 11,165 $ (147 ) $ 7,295 $ 7,430 $ 7,444 $ 14 December 31, 2016 December 31, 2015 TBA Securities by Issuer Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Fannie Mae $ 9,881 $ 10,251 $ 10,118 $ (133 ) $ 6,033 $ 6,145 $ 6,159 $ 14 Freddie Mac 1,035 1,060 1,047 (13 ) 689 703 703 — Ginnie Mae — 1 — (1 ) 573 582 582 — TBA securities, net $ 10,916 $ 11,312 $ 11,165 $ (147 ) $ 7,295 $ 7,430 $ 7,444 $ 14 _____________________ 1. Notional amount represents the par value (or principal balance) of the underlying Agency security. 2. Cost basis represents the forward price to be paid/(received) for the underlying Agency security. 3. Market value represents the current market value of the TBA contract (or of the underlying Agency security) as of period-end. 4. Net carrying value represents the difference between the market value and the cost basis 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 tables below summarize changes in our derivative and other hedge portfolio and their effect on our consolidated statements of comprehensive income for fiscal years 2016 , 2015 and 2014 (in millions): Fiscal Year 2016 Derivative and Other Hedging Instruments Notional Amount December 31, 2015 Additions Settlement, Termination, Expiration or Exercise Notional Amount December 31, 2016 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 7,295 116,439 (112,818 ) $ 10,916 $ (59 ) Interest rate swaps $ 40,525 15,650 (19,000 ) $ 37,175 (397 ) Payer swaptions $ 2,150 500 (1,450 ) $ 1,200 (3 ) U.S. Treasury securities - short position $ (1,714 ) (9,884 ) 3,537 $ (8,061 ) 134 U.S. Treasury securities - long position $ 25 961 (797 ) $ 189 7 U.S. Treasury futures contracts - short position $ (1,860 ) (7,840 ) 7,890 $ (1,810 ) (5 ) $ (323 ) ________________________________ 1. Excludes a net loss of $3 million from debt of consolidated VIEs and other miscellaneous net gains of $16 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Fiscal Year 2015 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount December 31, 2015 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 14,412 119,922 (127,039 ) $ 7,295 $ 305 Interest rate swaps $ 43,700 4,950 (8,125 ) $ 40,525 (932 ) Payer swaptions $ 6,800 1,500 (6,150 ) $ 2,150 (35 ) Receiver swaptions $ (4,250 ) — 4,250 $ — 4 U.S. Treasury securities - short position $ (5,392 ) (12,503 ) 16,181 $ (1,714 ) (68 ) U.S. Treasury securities - long position $ 2,411 33,525 (35,911 ) $ 25 (38 ) U.S. Treasury futures contracts - short position $ (730 ) (4,480 ) 3,350 $ (1,860 ) (12 ) $ (776 ) ______________________ 1. Excludes a net gain of $16 million from debt of consolidated VIEs and other miscellaneous net losses of $4 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Fiscal Year 2014 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount December 31, 2014 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 2,119 213,627 (201,334 ) $ 14,412 $ 1,117 Interest rate swaps $ 43,250 20,550 (20,100 ) $ 43,700 (1,838 ) Payer swaptions $ 14,250 5,250 (12,700 ) $ 6,800 (193 ) Receiver swaptions $ — (5,500 ) 1,250 $ (4,250 ) 11 U.S. Treasury securities - short position $ (2,007 ) (36,489 ) 33,104 $ (5,392 ) (420 ) U.S. Treasury securities - long position $ 3,927 18,549 (20,065 ) $ 2,411 66 U.S. Treasury futures contracts - short position $ (1,730 ) (2,920 ) 3,920 $ (730 ) (76 ) TBA put option $ — (150 ) 150 $ — — $ (1,333 ) ______________________ 1. Excludes a net gain of $75 million from investments in REIT equity securities, a net loss of $10 million from debt of consolidate VIEs and other miscellaneous net losses of $7 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income." id="sjs-B4">Derivative and Other Hedging Instruments As a function of our risk management strategy, we hedge a portion of our interest rate risk by entering into derivative and other hedging instrument contracts. The principal instruments that we use are interest rate swaps and interest rate swaptions and U.S. Treasury securities and U.S. Treasury futures contracts, primarily through short sales. We may also utilize TBA securities, purchase or write put or call options on TBA securities and other types of derivative instruments to hedge a portion of our risk. We also enter into TBA contracts as a means of investing in and financing Agency securities (thereby increasing our "at risk" leverage) or as a means of disposing of or reducing our exposure to Agency securities (thereby reducing our "at risk" leverage). Our risk management strategy attempts to manage the overall risk of the portfolio, reduce fluctuations in our net book value and generate additional income distributable to stockholders. 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 . Prior to September 30, 2011, our interest rate swaps were typically designated as cash flow hedges under ASC 815; however, as of September 30, 2011, we elected to discontinue hedge accounting for our interest rate swaps in order to increase our funding flexibility. For fiscal years 2016 , 2015 and 2014, we reclassified $39 million , $101 million and $156 million , respectively, of net deferred losses from accumulated OCI into interest expense related to our de-designated interest rate swaps and recognized an equal, but offsetting, amount in other comprehensive income. Our total net periodic interest costs on our swap portfolio were $294 million , $494 million and 486 million for fiscal years 2016 , 2015 and 2014, respectively. The difference between our total net periodic interest costs on our swap portfolio and the amount recorded in interest expense related to our de-designated hedges is reported in gain (loss) on derivative instruments and other securities, net in our accompanying consolidated statements of comprehensive income (totaling $255 million , $393 million and 330 million for fiscal years 2016 , 2015 and 2014, respectively). As of December 31, 2016 , all of the net deferred losses related to de-designated interest rate swaps had been reclassified from accumulated OCI into interest expense. 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, 2016 and 2015 (in millions): December 31, Derivative and Other Hedging Instruments Balance Sheet Location 2016 2015 Interest rate swaps Derivative assets, at fair value $ 321 $ 31 Swaptions Derivative assets, at fair value 22 17 TBA securities Derivative assets, at fair value 4 29 U.S. Treasury futures - short Derivative assets, at fair value 8 4 Total derivative assets, at fair value $ 355 $ 81 Interest rate swaps Derivative liabilities, at fair value $ (105 ) $ (920 ) TBA securities Derivative liabilities, at fair value (151 ) (15 ) Total derivative liabilities, at fair value $ (256 ) $ (935 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ 182 $ 25 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (7,636 ) (1,696 ) Total U.S. Treasury securities, net at fair value $ (7,454 ) $ (1,671 ) The following table summarizes our interest rate swap agreements outstanding as of December 31, 2016 and 2015 (dollars in millions): December 31, 2016 December 31, 2015 Payer Interest Rate Swaps Notional 1 Average Rate 2 Average 3 Net Average Notional 1 Average Rate 2 Average 3 Net Average ≤ 3 years $ 19,775 1.16% 0.92% $ 39 1.5 $ 14,775 1.06% 0.40% $ (23 ) 1.6 > 3 to ≤ 5 years 7,450 1.62% 0.91% 44 4.0 9,950 2.03% 0.40% (203 ) 4.0 > 5 to ≤ 7 years 4,725 1.89% 0.91% 28 5.9 7,175 2.47% 0.44% (230 ) 6.1 > 7 to ≤ 10 years 3,325 1.90% 0.91% 114 9.2 7,450 2.57% 0.39% (342 ) 8.3 > 10 years 1,900 2.64% 0.91% (9 ) 13.8 1,175 3.20% 0.39% (91 ) 14.7 Total $ 37,175 1.48% 0.92% $ 216 3.9 $ 40,525 1.89% 0.40% $ (889 ) 4.6 ________________________ 1. As of December 31, 2016 and 2015 , notional amount includes forward starting swaps of $0.6 billion and $4.5 billion , respectively, with an average forward start date of 1.2 and 0.7 years, respectively, and an average maturity of 10.7 and 5.5 years, respectively. 2. Average fixed pay rate includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.46% and 1.75% as of December 31, 2016 and 2015 , respectively. 3. Average receive rate excludes forward starting swaps. The following tables summarize our interest rate payer swaption agreements, U.S. Treasury securities and U.S. Treasury futures outstanding as of December 31, 2016 and 2015 (dollars in millions): Payer Swaptions Option Underlying Payer Swap Years to Expiration Cost Fair Value Average Months to Expiration Notional Amount Average Fixed Pay Rate Average Receive Rate (LIBOR) Average Term (Years) December 31, 2016 Total ≤ 1 year $ 52 $ 22 6 $ 1,200 3.06% 3M 8.3 December 31, 2015 Total ≤ 1 year $ 74 $ 17 4 $ 2,150 3.51% 3M 7.0 U.S. Treasury Securities December 31, 2016 December 31, 2015 Maturity Face Amount Net Long / (Short) Cost Basis Net Fair Value Face Amount Net Long / (Short) Cost Basis Net Fair Value 5 years $ (400 ) $ (404 ) $ (392 ) $ (250 ) $ (249 ) $ (249 ) 7 years (3,056 ) (3,041 ) (2,930 ) (354 ) (353 ) (352 ) 10 years (4,416 ) (4,236 ) (4,132 ) (1,085 ) (1,078 ) (1,070 ) Total U.S. Treasury securities, net $ (7,872 ) $ (7,681 ) $ (7,454 ) $ (1,689 ) $ (1,680 ) $ (1,671 ) U.S. Treasury Futures December 31, 2016 December 31, 2015 Maturity Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 5 years $ (730 ) $ (862 ) $ (859 ) $ 3 $ (730 ) $ (866 ) $ (864 ) $ 2 10 years (1,080 ) (1,347 ) (1,342 ) 5 (1,130 ) (1,424 ) (1,422 ) 2 Total U.S. Treasury futures $ (1,810 ) $ (2,209 ) $ (2,201 ) $ 8 $ (1,860 ) $ (2,290 ) $ (2,286 ) $ 4 _____________________ 1. U.S. Treasury futures notional amount represents the par value (or principal balance) of the underlying U.S. Treasury security. 2. U.S. Treasury futures cost basis represents the forward price to be paid/(received) for the underlying U.S. Treasury security. 3. U.S. Treasury futures market value represents the current market value of U.S. Treasury futures as of period-end. 4. Net carrying value represents the difference between the fair value and the cost basis of U.S. Treasury futures as of period-end and is reported in derivative assets/(liabilities), at fair value in our consolidated balance sheets. The following tables summarize our TBA securities as of December 31, 2016 and 2015 (in millions): December 31, 2016 December 31, 2015 TBA Securities by Coupon Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 15-Year TBA securities: 2.5% $ 1,853 $ 1,870 $ 1,856 $ (14 ) $ (80 ) $ (81 ) $ (80 ) $ 1 3.0% 292 302 300 (2 ) 225 233 232 (1 ) 3.5% 15 16 16 — 136 143 142 (1 ) Total 15-Year TBA securities 2,160 2,188 2,172 (16 ) 281 295 294 (1 ) 30-Year TBA securities: 3.0% 3,027 3,114 3,007 (107 ) 3,914 3,911 3,916 5 3.5% 1,209 1,251 1,236 (15 ) 1,497 1,536 1,539 3 4.0% 4,530 4,769 4,760 (9 ) 1,575 1,658 1,665 7 4.5% (10 ) (10 ) (10 ) — 28 30 30 — Total 30-Year TBA securities, net 8,756 9,124 8,993 (131 ) 7,014 7,135 7,150 15 Total TBA securities, net $ 10,916 $ 11,312 $ 11,165 $ (147 ) $ 7,295 $ 7,430 $ 7,444 $ 14 December 31, 2016 December 31, 2015 TBA Securities by Issuer Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Fannie Mae $ 9,881 $ 10,251 $ 10,118 $ (133 ) $ 6,033 $ 6,145 $ 6,159 $ 14 Freddie Mac 1,035 1,060 1,047 (13 ) 689 703 703 — Ginnie Mae — 1 — (1 ) 573 582 582 — TBA securities, net $ 10,916 $ 11,312 $ 11,165 $ (147 ) $ 7,295 $ 7,430 $ 7,444 $ 14 _____________________ 1. Notional amount represents the par value (or principal balance) of the underlying Agency security. 2. Cost basis represents the forward price to be paid/(received) for the underlying Agency security. 3. Market value represents the current market value of the TBA contract (or of the underlying Agency security) as of period-end. 4. Net carrying value represents the difference between the market value and the cost basis 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 tables below summarize changes in our derivative and other hedge portfolio and their effect on our consolidated statements of comprehensive income for fiscal years 2016 , 2015 and 2014 (in millions): Fiscal Year 2016 Derivative and Other Hedging Instruments Notional Amount December 31, 2015 Additions Settlement, Termination, Expiration or Exercise Notional Amount December 31, 2016 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 7,295 116,439 (112,818 ) $ 10,916 $ (59 ) Interest rate swaps $ 40,525 15,650 (19,000 ) $ 37,175 (397 ) Payer swaptions $ 2,150 500 (1,450 ) $ 1,200 (3 ) U.S. Treasury securities - short position $ (1,714 ) (9,884 ) 3,537 $ (8,061 ) 134 U.S. Treasury securities - long position $ 25 961 (797 ) $ 189 7 U.S. Treasury futures contracts - short position $ (1,860 ) (7,840 ) 7,890 $ (1,810 ) (5 ) $ (323 ) ________________________________ 1. Excludes a net loss of $3 million from debt of consolidated VIEs and other miscellaneous net gains of $16 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Fiscal Year 2015 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount December 31, 2015 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 14,412 119,922 (127,039 ) $ 7,295 $ 305 Interest rate swaps $ 43,700 4,950 (8,125 ) $ 40,525 (932 ) Payer swaptions $ 6,800 1,500 (6,150 ) $ 2,150 (35 ) Receiver swaptions $ (4,250 ) — 4,250 $ — 4 U.S. Treasury securities - short position $ (5,392 ) (12,503 ) 16,181 $ (1,714 ) (68 ) U.S. Treasury securities - long position $ 2,411 33,525 (35,911 ) $ 25 (38 ) U.S. Treasury futures contracts - short position $ (730 ) (4,480 ) 3,350 $ (1,860 ) (12 ) $ (776 ) ______________________ 1. Excludes a net gain of $16 million from debt of consolidated VIEs and other miscellaneous net losses of $4 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Fiscal Year 2014 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount December 31, 2014 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 2,119 213,627 (201,334 ) $ 14,412 $ 1,117 Interest rate swaps $ 43,250 20,550 (20,100 ) $ 43,700 (1,838 ) Payer swaptions $ 14,250 5,250 (12,700 ) $ 6,800 (193 ) Receiver swaptions $ — (5,500 ) 1,250 $ (4,250 ) 11 U.S. Treasury securities - short position $ (2,007 ) (36,489 ) 33,104 $ (5,392 ) (420 ) U.S. Treasury securities - long position $ 3,927 18,549 (20,065 ) $ 2,411 66 U.S. Treasury futures contracts - short position $ (1,730 ) (2,920 ) 3,920 $ (730 ) (76 ) TBA put option $ — (150 ) 150 $ — — $ (1,333 ) ______________________ 1. Excludes a net gain of $75 million from investments in REIT equity securities, a net loss of $10 million from debt of consolidate VIEs and other miscellaneous net losses of $7 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income.

Pledged Assets

Pledged Assets	12 Months Ended
	Dec. 31, 2016
Pledged Assets [Abstract]
Pledged Assets	30 and ≤ 60 days 8,103 8,158 23 8,311 8,340 23 > 60 and ≤ 90 days 4,034 4,070 11 7,534 7,525 21 > 90 days 11,278 11,380 32 12,207 12,187 34 Total MBS 43,096 43,471 122 48,105 48,127 135 U.S. Treasury securities: 1 day — — — 25 25 — > 1 day ≤ 30 days 173 173 — — — — Total $ 43,269 $ 43,644 $ 122 $ 48,130 $ 48,152 $ 135 ______________________ 1. Includes $181 million and $245 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of December 31, 2016 and 2015 , respectively. As of December 31, 2016 and 2015 , none of our borrowings backed by RMBS were due on demand or mature overnight. The table above excludes Agency securities transferred to our consolidated VIEs. Securities transferred to our consolidated VIEs can only be used to settle the obligations of each respective VIE. However, we may pledge our retained interests in our consolidated VIEs as collateral under our repurchase agreements and derivative contracts. Please refer to Notes 3 and 4 for additional information regarding our consolidated VIEs. Assets Pledged from Counterparties As of December 31, 2016 and 2015 , we had assets pledged to us from counterparties as collateral under our reverse repurchase, repurchase and derivative agreements summarized in the tables below (in millions). December 31, 2016 December 31, 2015 Assets Pledged to AGNC Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total Agency MBS - fair value $ — $ — $ 14 $ 14 $ — $ — $ — $ — U.S. Treasury securities - fair value 7,636 — — 7,636 1,702 — — 1,702 Cash — 107 — 107 — — — — Total $ 7,636 $ 107 $ 14 $ 7,757 $ 1,702 $ — $ — $ 1,702 U.S Treasury securities received as collateral under our reverse repurchase agreements that we use to cover short sales of U.S. Treasury securities are accounted for as securities borrowing transactions. We recognize a corresponding obligation to return the borrowed securities at fair value on the accompanying consolidated balance sheets based on the value of the underlying borrowed securities as of the reporting date. Cash collateral received is recognized in cash and cash equivalents with a corresponding amount recognized in accounts payable and other accrued liabilities on the accompanying consolidated balance sheets. 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, 2016 and 2015 (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, 2016 Interest rate swap and swaption agreements, at fair value 1 $ 342 $ — $ 342 $ (80 ) $ (49 ) $ 213 TBA 4 — 4 (4 ) — — Receivable under reverse repurchase agreements 7,716 — 7,716 (6,963 ) (753 ) — Total $ 8,062 $ — $ 8,062 $ (7,047 ) $ (802 ) $ 213 December 31, 2015 Interest rate swap and swaption agreements, at fair value 1 $ 48 $ — $ 48 $ (31 ) $ — $ 17 TBA 29 — 29 (15 ) — 14 Receivable under reverse repurchase agreements 1,713 — 1,713 (1,356 ) (357 ) — Total $ 1,790 $ — $ 1,790 $ (1,402 ) $ (357 ) $ 31 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, 2016 Interest rate swap agreements, at fair value 1 $ 105 $ — $ 105 $ (80 ) $ (25 ) $ — TBA 151 — 151 (4 ) (147 ) — Repurchase agreements and FHLB advances 40,895 — 40,895 (6,963 ) (33,932 ) — Total $ 41,151 $ — $ 41,151 $ (7,047 ) $ (34,104 ) $ — December 31, 2015 Interest rate swap agreements, at fair value 1 $ 920 $ — $ 920 $ (31 ) $ (889 ) $ — TBA 15 15 (15 ) — — Repurchase agreements and FHLB advances 45,507 — 45,507 (1,356 ) (44,151 ) — Total $ 46,442 $ — $ 46,442 $ (1,402 ) $ (45,040 ) $ — _______________________ 1. Reported under derivative assets/liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 5 for a reconciliation of derivative assets/liabilities, at fair value to their sub-components. 2. Includes cash and securities pledged/received as collateral, at fair value. Amounts presented are limited to collateral pledged sufficient to reduce the net amount to zero for individual counterparties, as applicable." 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 collateral upon execution of derivative transactions, such as under our interest rate swap agreements and TBA contracts. Our prime brokerage agreements, pursuant to which we receive custody and settlement services, also require that we post minimum 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 in the event that 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 provided for 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 and clearinghouse guarantee funds and other resources that are available in the event of a clearing member default. Further, each of our International Swaps and Derivatives Association ("ISDA") Master Agreements also contains a cross default provision under which a default under certain of our other indebtedness in excess of certain thresholds causes an event of default under the ISDA Master Agreement. Threshold amounts vary by lender. Following an event of default, we could be required to settle our obligations under the agreements. Additionally, under certain of our ISDA Master Agreements, we could be required to settle our obligations under the agreements if we fail to maintain certain minimum stockholders' equity thresholds or our REIT status or if we fail to comply with limits on our leverage up to certain specified levels. As of December 31, 2016 , the fair value of additional collateral that could be required to be posted as a result of the credit-risk-related contingent features being triggered was not material to our financial statements. As of December 31, 2016 , our maximum amount at risk with any counterparty related to our repurchase agreements was less than 6% of our stockholders' equity and our maximum amount at risk with any counterparty related to our interest rate swap and swaption agreements, excluding centrally cleared swaps, was less than 1% of our stockholders' equity. The following table summarizes certain characteristics of our repurchase agreements outstanding with counterparties representing amounts at risk greater than or equal to 5% of our stockholders' equity as of December 31, 2016 (dollars in millions). As of December 31, 2015 the maximum amount of risk with any counterparty related to our repurchase agreements was less than 5% of our stockholders equity. December 31, 2016 Amount Outstanding Net Counterparty Exposure 1 Percent of Equity Weighted Average Months to Maturity J.P. Morgan Securities, LLC $ 4,875 $ 405 5.5 % 34 ______________________ 1. Represents the net carrying value of the securities pledged under repurchase agreements, including accrued interest plus any cash or assets on deposit to secure the repurchase obligation, less the amount of the repurchase liability, including accrued interest. Assets Pledged to Counterparties The following tables summarize our assets pledged as collateral under our funding, derivative and prime broker agreements by type, including securities pledged related to securities sold but not yet settled, as of December 31, 2016 and 2015 (in millions): December 31, 2016 Assets Pledged to Counterparties Repurchase Agreements and FHLB Advances 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements Total Agency RMBS - fair value $ 43,005 $ 818 $ 275 $ 865 $ 44,963 Non-Agency RMBS - fair value 90 — — — 90 U.S. Treasury securities - fair value 173 — — — 173 Accrued interest on pledged securities 122 3 1 2 128 Restricted cash and cash equivalents 60 — 14 — 74 Total $ 43,450 $ 821 $ 290 $ 867 $ 45,428 ______________________ 1. Includes $181 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements. December 31, 2015 Assets Pledged to Counterparties Repurchase Agreements and FHLB Advances 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements Total Agency RMBS - fair value $ 47,992 $ 1,029 $ 148 $ 485 $ 49,654 Non-Agency RMBS - fair value 113 — — — 113 U.S. Treasury securities - fair value 25 — — — 25 Accrued interest on pledged securities 135 3 — 2 140 Restricted cash and cash equivalents 23 — 1,226 32 1,281 Total $ 48,288 $ 1,032 $ 1,374 $ 519 $ 51,213 ______________________ 1. Includes $245 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements. As of December 31, 2016 and 2015 , we held $126 million and $150 million , respectively, of membership and activity-based stock in the FHLB of Des Moines. FHLB stock is reported at cost, which equals par value, in other assets on our accompanying consolidated balance sheets. FHLB stock can only be redeemed or sold at its par value, and only to the FHLB of Des Moines. The cash and cash equivalents and Agency securities pledged as collateral under our derivative agreements are included in restricted cash and cash equivalents and Agency securities, at fair value, respectively, on our consolidated balance sheets. The following table summarizes our securities pledged as collateral under our repurchase agreements and FHLB advances by the remaining maturity of our borrowings, including securities pledged related to sold but not yet settled securities, as of December 31, 2016 and 2015 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 4 . December 31, 2016 December 31, 2015 Securities Pledged by Remaining Maturity of Repurchase Agreements and FHLB Advances 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 RMBS: 1 ≤ 30 days $ 19,681 $ 19,863 $ 56 $ 20,053 $ 20,075 $ 57 > 30 and ≤ 60 days 8,103 8,158 23 8,311 8,340 23 > 60 and ≤ 90 days 4,034 4,070 11 7,534 7,525 21 > 90 days 11,278 11,380 32 12,207 12,187 34 Total MBS 43,096 43,471 122 48,105 48,127 135 U.S. Treasury securities: 1 day — — — 25 25 — > 1 day ≤ 30 days 173 173 — — — — Total $ 43,269 $ 43,644 $ 122 $ 48,130 $ 48,152 $ 135 ______________________ 1. Includes $181 million and $245 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of December 31, 2016 and 2015 , respectively. As of December 31, 2016 and 2015 , none of our borrowings backed by RMBS were due on demand or mature overnight. The table above excludes Agency securities transferred to our consolidated VIEs. Securities transferred to our consolidated VIEs can only be used to settle the obligations of each respective VIE. However, we may pledge our retained interests in our consolidated VIEs as collateral under our repurchase agreements and derivative contracts. Please refer to Notes 3 and 4 for additional information regarding our consolidated VIEs. Assets Pledged from Counterparties As of December 31, 2016 and 2015 , we had assets pledged to us from counterparties as collateral under our reverse repurchase, repurchase and derivative agreements summarized in the tables below (in millions). December 31, 2016 December 31, 2015 Assets Pledged to AGNC Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total Agency MBS - fair value $ — $ — $ 14 $ 14 $ — $ — $ — $ — U.S. Treasury securities - fair value 7,636 — — 7,636 1,702 — — 1,702 Cash — 107 — 107 — — — — Total $ 7,636 $ 107 $ 14 $ 7,757 $ 1,702 $ — $ — $ 1,702 U.S Treasury securities received as collateral under our reverse repurchase agreements that we use to cover short sales of U.S. Treasury securities are accounted for as securities borrowing transactions. We recognize a corresponding obligation to return the borrowed securities at fair value on the accompanying consolidated balance sheets based on the value of the underlying borrowed securities as of the reporting date. Cash collateral received is recognized in cash and cash equivalents with a corresponding amount recognized in accounts payable and other accrued liabilities on the accompanying consolidated balance sheets. 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, 2016 and 2015 (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, 2016 Interest rate swap and swaption agreements, at fair value 1 $ 342 $ — $ 342 $ (80 ) $ (49 ) $ 213 TBA 4 — 4 (4 ) — — Receivable under reverse repurchase agreements 7,716 — 7,716 (6,963 ) (753 ) — Total $ 8,062 $ — $ 8,062 $ (7,047 ) $ (802 ) $ 213 December 31, 2015 Interest rate swap and swaption agreements, at fair value 1 $ 48 $ — $ 48 $ (31 ) $ — $ 17 TBA 29 — 29 (15 ) — 14 Receivable under reverse repurchase agreements 1,713 — 1,713 (1,356 ) (357 ) — Total $ 1,790 $ — $ 1,790 $ (1,402 ) $ (357 ) $ 31 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, 2016 Interest rate swap agreements, at fair value 1 $ 105 $ — $ 105 $ (80 ) $ (25 ) $ — TBA 151 — 151 (4 ) (147 ) — Repurchase agreements and FHLB advances 40,895 — 40,895 (6,963 ) (33,932 ) — Total $ 41,151 $ — $ 41,151 $ (7,047 ) $ (34,104 ) $ — December 31, 2015 Interest rate swap agreements, at fair value 1 $ 920 $ — $ 920 $ (31 ) $ (889 ) $ — TBA 15 15 (15 ) — — Repurchase agreements and FHLB advances 45,507 — 45,507 (1,356 ) (44,151 ) — Total $ 46,442 $ — $ 46,442 $ (1,402 ) $ (45,040 ) $ — _______________________ 1. Reported under derivative assets/liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 5 for a reconciliation of derivative assets/liabilities, at fair value to their sub-components. 2. Includes cash and securities pledged/received as collateral, at fair value. Amounts presented are limited to collateral pledged sufficient to reduce the net amount to zero for individual counterparties, as applicable.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We determine the fair value of our investment securities and debt of consolidated VIEs based upon fair value estimates obtained from multiple third party pricing services and dealers. In determining fair value, third party pricing sources use various valuation approaches, including market and income approaches. Factors used by third party sources in estimating the fair value of an instrument may include observable inputs such as coupons, primary and secondary mortgage rates, pricing information, credit data, volatility statistics, and other market data that are current as of the measurement date. 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 foreclosures, 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. For further information regarding valuation of our derivative instruments, please refer to the discussion of derivative and other hedging instruments in Note 2 . We review the various third party fair value estimates and perform procedures to validate their reasonableness, including an analysis of the range of third party estimates for each position, comparison to recent trade activity for similar securities, and management review for consistency with market conditions observed as of the measurement date. While we do not adjust prices we obtain from third party pricing sources, we will exclude third party prices for securities from our determination of fair value if we determine (based on our validation procedures and our market knowledge and expertise) that the price is significantly different from 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 classification. We utilize a three-level valuation hierarchy for disclosure of fair value measurement. 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. There were no transfers between hierarchy levels during fiscal years December 31, 2016 . The three levels of 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 following table provides a summary of our assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2016 and 2015 (in millions): December 31, 2016 December 31, 2015 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 45,393 $ — $ — $ 51,331 $ — Agency securities transferred to consolidated VIEs — 818 — — 1,029 — Non-Agency securities — 124 — — 113 — Credit risk transfer securities — 164 — — — — U.S. Treasury securities 182 — — 25 — — Interest rate swaps — 321 — — 31 — Swaptions — 22 — — 17 — TBA securities — 4 — — 29 — U.S. Treasury futures 8 — — 4 — — REIT equity securities — — — 33 — — Total $ 190 $ 46,846 $ — $ 62 $ 52,550 $ — Liabilities: Debt of consolidated VIEs $ — $ 460 $ — $ — $ 595 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 7,636 — — 1,696 — — Interest rate swaps — 105 — — 920 — TBA securities — 151 — — 15 — Total $ 7,636 $ 716 $ — $ 1,696 $ 1,530 $ — We elected the option to account for debt of consolidated VIEs at fair value with changes in fair value reflected in earnings during the period in which they occur, because we believe this election more appropriately reflects our financial position as both the consolidated Agency securities and consolidated debt are presented in a consistent manner, at fair value, on our consolidated balance sheets. We estimate the fair value of the consolidated debt based on difference between the fair value of the RMBS transferred to consolidated VIEs and the fair value of our retained interests, each of which is based on valuations obtained from third-party pricing services and non-binding dealer quotes derived from common market pricing methods using "Level 2" inputs, and are more observable than using inputs to estimate the fair value of the consolidated debt on a stand-alone basis. 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 and FHLB advances, 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 and FHLB advances, due to floating rates of interest based 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.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Preferred Stock Pursuant to our amended and restated certificate of incorporation, we are authorized to designate and issue up to 10.0 million shares of preferred stock in one or more classes or series. Our Board of Directors has designated 6.9 million shares as 8.000% Series A Cumulative Redeemable Preferred Stock ("Series A Preferred Stock") and 8,050 shares as 7.750% Series B Cumulative Redeemable Preferred Stock ("Series B Preferred Stock"). As of December 31, 2016 , we had 3.1 million shares of authorized but unissued shares of preferred stock. Our Board of Directors may designate additional series of authorized preferred stock ranking junior to or in parity with the Series A or Series B Preferred Stock or designate additional shares of the Series A or Series B Preferred Stock and authorize the issuance of such shares. In April 2012 , we completed a public offering in which 6.9 million shares of our Series A Preferred Stock were sold to the underwriters at a price of $24.2125 per share for proceeds, net of offering expenses, of $167 million . In May 2014 , we completed a public offering in which 7.0 million depositary shares were sold to the underwriters at a price of $24.2125 per depositary share for proceeds, net of offering expenses, of $169 million . Each depositary share represents a 1/1,000th interest in a share of our Series B Preferred Stock. Our Series A and Series B Preferred Stock have no stated maturity, are not subject to any sinking fund or mandatory redemption and rank on parity with each other. Under certain circumstances upon a change of control, our Series A and Series B Preferred Stock are convertible to shares of our common stock. Holders of our Series A Preferred Stock and depository shares underlying our Series B Preferred Stock have no voting rights, except under limited conditions, and are entitled to receive cumulative cash dividends at a rate of 8.000% and 7.750% per annum, respectively, of their $25.00 per share and $25.00 per depositary share liquidation preference, respectively, before holders of our common stock are entitled to receive any dividends. Shares of our Series A Preferred Stock and depository shares underlying our Series B Preferred Stock are each redeemable at $25.00 per share, plus accumulated and unpaid dividends (whether or not declared) exclusively at our option commencing on April 5, 2017 and May 8, 2019 , respectively, or earlier under certain circumstances intended to preserve our qualification as a REIT for federal income tax purposes. Dividends are payable quarterly in arrears on the 15th day of each January, April, July and October. As of December 31, 2016 , we had declared all required quarterly dividends on our Series A and Series B Preferred Stock. Common Stock Repurchase Program In October 2012, our Board of Directors adopted a program that provided for stock repurchases, which, as amended, authorized repurchases of our common stock up to $2 billion through December 31, 2016. In October 2016, our Board of Directors terminated the existing stock repurchase program, which had a total of $0.6 billion remaining for authorized repurchases of our common stock, and replaced it with a new stock repurchase authorization. Under the new stock repurchase program, we are authorized to repurchase up to $1 billion of our outstanding shares of common stock through December 31, 2017. Shares of our common stock may be purchased in the open market, including through block purchases, or through privately negotiated transactions, or pursuant to any trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended. The timing, manner, price and amount of any repurchases will be determined at our discretion and the program may be suspended, terminated or modified at any time for any reason. Among other factors, we intend to only consider repurchasing shares of our common stock when the purchase price is less than our estimate of our current tangible net asset value per common share. Generally, when we repurchase our common stock at a discount to our tangible net asset value, the tangible net asset value of our remaining shares of common stock outstanding increases. In addition, we do not intend to repurchase any shares from directors, officers or other affiliates. The program does not obligate us to acquire any specific number of shares, and all repurchases will be made in accordance with Rule 10b-18, which sets certain restrictions on the method, timing, price and volume of stock repurchases. During the fiscal years 2016 , 2015 and 2014, we repurchased 6.5 million , 15.3 million , and 3.4 million shares of our common stock at an average repurchase price of $17.89 , $18.58 and $22.10 per share, including expenses, totaling $116 million , $285 million and $74 million . As of December 31, 2016 , the total remaining amount authorized for repurchases of our common stock was $1 billion . Distributions to Stockholders The following table summarizes cash dividends declared for fiscal years 2016 , 2015 and 2014 (in millions, except per share amounts): Dividends Declared Dividends Declared Per Share 8.000 % Series A Cumulative Redeemable Preferred Stock Fiscal year 2016 $ 14 $ 2.000000 Fiscal year 2015 $ 14 $ 2.000000 Fiscal year 2014 $ 14 $ 2.000000 7.750% Series B Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2016 $ 14 $ 1.937500 Fiscal year 2015 $ 14 $ 1.937500 Fiscal year 2014 $ 6 $ 0.844965 Common Stock Fiscal year 2016 $ 763 $ 2.300000 Fiscal year 2015 $ 863 $ 2.480000 Fiscal year 2014 $ 921 $ 2.610000 Accumulated Other Comprehensive Income (Loss) The following table summarizes changes to accumulated OCI for fiscal years 2016 , 2015 and 2014 (in millions): Accumulated Other Comprehensive Income (Loss) Net Unrealized Gain (Loss) on Available-for-Sale MBS Net Unrealized Gain (Loss) on Swaps Total Accumulated OCI Balance Balance as of December 31, 2013 $ (1,087 ) $ (296 ) $ (1,383 ) OCI before reclassifications 1,708 — 1,708 Amounts reclassified from accumulated OCI (51 ) 156 105 Balance as of December 31, 2014 570 (140 ) 430 OCI before reclassifications (620 ) — (620 ) Amounts reclassified from accumulated OCI 23 101 124 Balance as of December 31, 2015 (27 ) (39 ) (66 ) OCI before reclassifications (261 ) — (261 ) Amounts reclassified from accumulated OCI (109 ) 39 (70 ) Balance as of December 31, 2016 $ (397 ) $ — $ (397 ) The following table summarizes reclassifications out of accumulated OCI for fiscal years 2016 and 2015 (in millions): Fiscal Year Line Item in the Consolidated Statements of Comprehensive Income Where Net Income is Presented Amounts Reclassified from Accumulated OCI 2016 2015 2014 (Gain) loss amounts reclassified from accumulated OCI for available-for-sale MBS upon realization $ (109 ) $ 23 $ (51 ) Gain (loss) on sale of mortgage-backed securities, net Periodic interest costs of interest rate swaps previously designated as hedges under GAAP, net 39 101 156 Interest expense Total reclassifications $ (70 ) $ 124 $ 105

Equity Incentive Plan (Notes)

Equity Incentive Plan (Notes)	12 Months Ended
	Dec. 31, 2016
Share-based Compensation [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	Equity Incentive Plans We sponsor an equity incentive plan to provide for the issuance of equity-based awards, including stock options, restricted stock, restricted stock units and unrestricted stock awards to our independent directors (the "Director Plan"). During fiscal years 2016 , 2015 and 2014, we granted restricted stock unit ("RSU") awards under the plan totaling $625,000 , $625,000 and $375,000 , respectively. The awards represent the right to receive an equivalent number of shares of common stock as measured by the closing price of our common stock on the grant date, plus any equivalent shares for dividends declared on our common stock, and vest over a 13 month period, subject to the terms and conditions of the plan. Prior to fiscal year 2013, we granted restricted stock awards under the Plan. The restricted stock awards had a grant date fair value equal to the closing price of our common stock on such date and vested annually over three years. The Director Plan was terminated and succeeded in its entirety by the 2016 Equity and Incentive Compensation Plan (the "2016 Equity Plan"), which was approved by our stockholders on December 9, 2016. Outstanding awards under the Director Plan, however, will continue in effect in accordance with their terms. The following table summarizes restricted stock and RSU transactions under the Director Plan for fiscal years 2016 , 2015 and 2014: Director Plan Shares of Restricted Stock Restricted Stock Units Weighted Average Grant Date Fair Value 1 Weighted Average Vest Date Fair Value 2 Unvested balance as of December 31, 2013 27,000 — $ 30.37 $ — Granted — 16,770 $ 22.36 $ — Accrued RSU dividend equivalents — 1,469 $ — $ — Vested (13,000 ) — $ 30.01 $ 22.01 Unvested balance as of December 31, 2014 14,000 18,239 $ 25.11 $ — Granted — 28,880 $ 21.64 $ — Accrued RSU dividend equivalents — 3,319 $ — $ — Vested (9,000 ) (19,007 ) $ 23.17 $ 21.03 Unvested balance as of December 31, 2015 5,000 31,431 $ 21.44 $ — Granted — 33,015 $ 18.93 $ — Accrued RSU dividend equivalents — 3,527 $ — $ — Vested (5,000 ) (46,538 ) $ 20.00 $ 18.99 Unvested balance as of December 31, 2016 — 21,435 $ 17.49 $ — _______________________ 1. Accrued RSU dividend equivalents have a weighted average grant date fair value of $0. 2. Weighted average vest date fair value is based on the closing price of our common stock on the vest date. The 2016 Equity Plan provides for grants of equity-based compensation in the form of stock options, appreciation rights ("SARs"), restricted shares, RSUs, performance shares, performance units, dividend equivalents and certain other awards denominated or payable in, or otherwise based on, shares of our common stock, plus cash incentive awards, for the purpose of providing our non-employee directors, officers and other employees, and those of our subsidiaries, incentives and rewards for service or performance. The 2016 Equity Plan authorizes a total of 10 million shares our common stock that may be used to satisfy awards under the plan, subject to the share counting rules set forth within the plan. The Compensation Committee of our Board of Directors determines awards to be granted under the 2016 Equity Plan and the terms of such awards, including vesting schedules. During fiscal year 2016 , we granted RSU awards under the plan totaling $2 million . The awards represent the right to receive an equivalent number of shares of common stock as measured by the closing price of our common stock on the grant date, or 101,407 shares, plus any equivalent shares for dividends declared on our common stock, and vest over a three year period, subject to the terms and conditions of the plan. As of December 31, 2016 , 9.9 million shares remained available for awards under the 2016 Equity Plan, excluding securities to be issued for prior awards granted under the plan. We recognize the cost of equity-based compensation awards based on the grant-date fair value of those awards, or the fair value of liabilities incurred, over the requisite service period. We recognize the impact of forfeitures as they occur. During fiscal years 2016 , 2015 and 2014, we recognized other operating expense of $731,000 , $704,000 and $540,000 , respectively, under the Director Plan and during fiscal year 2016 we recognized compensation expense of $28,000 under the 2016 Equity Plan. As of December 31, 2016 , we had unrecognized expense related to awards granted under the plans of approximately $2 million , which is expected to be recognized over a weighted average period of 2.8 years.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We elected to be taxed as a REIT under the provisions of the Internal Revenue Code and the corresponding provisions of state law, commencing with our initial tax year ended December 31, 2008. In order to continue to qualify as a REIT, we must annually distribute, in a timely manner to our stockholders, at least 90% of our taxable ordinary income, amongst other conditions. A REIT is generally not subject to U.S. federal and state corporate income tax on its earnings to the extent that it distributes its annual taxable net income to its stockholders and as long as certain asset, income and stock ownership tests are met. We operate in a manner that will allow us to be taxed as a REIT. As permitted by the Internal Revenue Code, a REIT can designate dividends paid in the subsequent year as dividends of the current year if those dividends are both declared by the extended due date of the REIT's federal income tax return and paid to stockholders by the last day of the subsequent year; however, we may still be subject to a non-deductible 4% excise tax if the actual amount distributed to our stockholders in a calendar year is less than the minimum amount specified under federal tax laws. We have a wholly-owned subsidiary for which we elected to treat as taxable REIT subsidiary. As such it is subject to federal and state income tax based on its taxable income. All other subsidiaries are disregarded entities for U.S. federal income tax purposes. As such, their assets, liabilities and income are generally treated as our assets, liabilities and income for purposes of U.S. federal and state corporate income taxes. We evaluate uncertain income tax positions, if any, in accordance with ASC Topic 740, Income Taxes ("ASC 740"). To the extent we incur interest and/or penalties in connection with our tax obligations, such amounts shall be classified as income tax expense on our consolidated statements of operations. Income Taxes As of December 31, 2016 , we have distributed all of our estimated taxable income for fiscal year 2016 . Accordingly, we do not expect to incur an income tax liability on our 2016 taxable income. For fiscal years 2015 and 2014, we distributed all of our taxable income within the 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, 2016 , 2015 and 2014. Our tax returns for tax years 2013 and forward are open to examination by the IRS. In the event that we incur income tax related interest and penalties, our policy is to classify them as a component of provision for income taxes.

Management Agreement and Relate

Management Agreement and Related Party Transactions (Notes)	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Management Agreement and Related Party Transactions	Management Agreement and Related Party Transactions Prior to our acquisition of AMM on July 1, 2016, we were externally managed by AGNC Management, LLC (our "Manager"). We paid our Manager a management fee payable monthly in arrears in an amount equal to one-twelfth of 1.25% of our month-end stockholders' equity, adjusted to exclude the effect of any unrealized gains or losses included in either retained earnings or accumulated OCI, each as computed in accordance with GAAP. There was no incentive compensation payable to our Manager pursuant to the management agreement. We incurred management fees of $52 million , $116 million and $119 million for the first half of fiscal year 2016 and for fiscal years 2015 and 2014, respectively. Following our management internalization, we no longer incur a management fee, but we incur expenses associated with an internally managed organization, including compensation expense previously borne by our Manager. For fiscal year 2016 , we had compensation and benefits expense of $19 million , consisting of base salary, bonus accruals and benefits expense. Our management agreement provided for automatic annual one-year renewal terms and could only be terminated by us or our Manager without cause, as defined in the management agreement, after the completion of the then current renewal term, provided that either party provided 180-days prior written notice of non-renewal of the management agreement. If we were to not renew the management agreement without cause, we would have been required to pay a termination fee on the last day of the applicable term, equal to three times the average annual management fee earned by our Manager during the prior 24-month period immediately preceding the most recently completed month prior to the effective date of termination. We could only not renew the management agreement with or without cause with the consent of the majority of our independent directors. Pursuant to our management agreement, we were also obligated to reimburse our Manager for its expenses incurred directly related to our operations, excluding employment-related expenses of our Manager's officers and employees and any American Capital employees who provided services to us pursuant to the management agreement. For fiscal years 2016 , 2015 and 2014, we recorded expense reimbursements to our Manager of $3 million , $8 million and $8 million , respectively, primarily consisting of costs related to information technology systems. During fiscal year 2016, following our acquisition of AMM, we earned management fees of $8 million from our management of MTGE.

Business Combination - Acquisit

Business Combination - Acquisition of AGNC Mortgage Management, LLC (Notes)	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	Business Combination - Acquisition of AGNC Mortgage Management, LLC On July 1, 2016 , we completed our acquisition of all of the outstanding membership interests of AMM from ACAM, a wholly owned portfolio company of ACAS, for a purchase price of $562 million in cash. Following the closing of the acquisition, we became internally managed and are no longer affiliated with ACAS. The results of AMM's operations have been included in our consolidated financial statements since that date. We believe internalizing our management function will result in lower operating costs as well as provide management fee income from MTGE. Our acquisition of AMM is accounted for as a business combination using the acquisition method of accounting, whereby the total purchase price has been allocated to identifiable assets acquired and liabilities assumed based on their respective fair values as of the acquisition date. Goodwill is calculated as the excess of the consideration transferred over the net assets acquired that meet the criteria for separate recognition and represents the estimated future economic benefits arising from these and other assets acquired that could not be individually identified or do not qualify for recognition as a separate asset. A large majority of the acquisition price has been recognized as goodwill, which is attributable to our pre-existing management agreement with AMM that does not qualify for separate recognition. Goodwill is expected to be deductible for income tax purposes over a 15 year amortization period. We did not recognize a gain or loss associated with the effective settlement of our management agreement with AMM on the acquisition date based on comparable agreements available in the market. The fair values of intangible assets acquired were determined using a market-based measurement under the income approach based on primarily unobservable market data that cannot be corroborated and, thus, represent a level 3 measurement (see Note 7 ). The primary market-based inputs include forecasted revenues and expenses, discount rate and corporate income tax rate. The following table summarizes the fair values of assets acquired and liabilities assumed at the acquisition date (in millions). July 1, 2016 (Acquisition Date) Cash $ 7 MTGE management agreement 29 Other intangible asset 1 Total identifiable assets 37 Accounts payable and other liabilities (1 ) Identifiable net assets acquired 36 Goodwill 526 Net assets acquired $ 562 The MTGE management agreement is being amortized over a 10 year amortization period. We recognized $9 million of transaction related costs that were expensed during fiscal year 2016 . These costs are included in other operating expenses in our consolidated statements of comprehensive income. AMM's revenue and net loss included in our consolidated statements of comprehensive income from the acquisition date to December 31, 2016 are $8 million and $(11) million , respectively, after elimination of AGNC's management fee and other intercompany transactions. The following table represents our pro forma consolidated revenue and net income as if AMM had been included in our consolidated results for fiscal year 2015 and for all of fiscal year 2016 (in millions). Revenue includes interest income from our investment portfolio and management fee income from managing MTGE. Amounts have been calculated after applying our accounting policies and adjusting AMM's results to reflect amortization expense that would have been charged assuming the fair value adjustments to intangible assets had been applied on January 1, 2015. All AGNC management fees and all other actual and pro forma intercompany transactions have been eliminated. These pro forma results have been prepared for comparative purposes only and do not purport to be indicative of what operating results would have been had the AMM acquisition occurred on January 1, 2015 and may not be indicative of future operating results. Pro Forma Consolidated Revenue and Net Income Fiscal Year 2016 2015 Revenue $ 1,337 $ 1,483 Net Income $ 661 $ 303

Quarterly Results Quarterly Res

Quarterly Results Quarterly Results (Notes)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results	uarterly Results (Unaudited) The following is a presentation of the quarterly results of operations and comprehensive income for fiscal years 2016 and 2015 (in millions, except per share data). Quarter Ended March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 Interest income: Interest income $ 295 $ 318 $ 315 $ 393 Interest expense 99 101 96 98 Net interest income 196 217 219 295 Other gain (loss): Gain (loss) on sale of investment securities, net (2 ) 55 61 (5 ) Unrealized gain (loss) on investment securities measured at fair value through net income, net 11 — (6 ) (11 ) Gain (loss) on derivative instruments and other securities, net (944 ) (367 ) 248 753 Management fee income — — 4 4 Total other gain (loss), net (935 ) (312 ) 307 741 Expenses: Management fee expense 27 25 — — Compensation and benefits — — 9 10 Other operating expenses 6 15 6 7 Total expenses 33 40 15 17 Net income (loss) (772 ) (135 ) 511 1,019 Dividend on preferred stock 7 7 7 7 Net income (loss) available (attributable) to common shareholders $ (779 ) $ (142 ) $ 504 $ 1,012 Net income (loss) $ (772 ) $ (135 ) $ 511 $ 1,019 Other comprehensive income (loss): Unrealized gain (loss) on available-for-sale securities, net 765 370 (97 ) (1,408 ) Unrealized gain on derivative instruments, net 19 12 7 1 Other comprehensive income (loss) 784 382 (90 ) (1,407 ) Comprehensive income (loss) 12 247 421 (388 ) Dividend on preferred stock 7 7 7 7 Comprehensive income (loss) available (attributable) to common shareholders $ 5 $ 240 $ 414 $ (395 ) Weighted average number of common shares outstanding - basic and diluted 334.4 331.0 331.0 331.0 Net income (loss) per common share - basic and diluted $ (2.33 ) $ (0.43 ) $ 1.52 $ 3.06 Comprehensive income (loss) per common share - basic and diluted $ 0.01 $ 0.73 $ 1.25 $ (1.19 ) Dividends declared per common share $ 0.60 $ 0.60 $ 0.56 $ 0.54 Quarter Ended March 31, June 30, 2015 September 30, December 31, 2015 Interest income: Interest income $ 383 $ 414 $ 295 $ 374 Interest expense 86 81 77 86 Net interest income 297 333 218 288 Other gain (loss): Gain (loss) on sale of investment securities, net 36 (22 ) (39 ) 2 Unrealized gain (loss) on investment securities measured at fair value through net income, net 11 (7 ) 10 (9 ) Gain (loss) on derivative instruments and other securities, net (560 ) 244 (788 ) 340 Total other gain (loss), net (513 ) 215 (817 ) 333 Expenses: Management fees 30 29 29 28 General and administrative expenses 6 7 5 5 Total expenses 36 36 34 33 Net income (loss) (252 ) 512 (633 ) 588 Dividend on preferred stock 7 7 7 7 Net income (loss) available (attributable) to common shareholders $ (259 ) $ 505 $ (640 ) $ 581 Net income (loss) $ (252 ) $ 512 $ (633 ) $ 588 Other comprehensive income (loss): Unrealized gain (loss) on available-for-sale securities, net 391 (872 ) 467 (583 ) Unrealized gain on derivative instruments, net 29 26 24 22 Other comprehensive income (loss) 420 (846 ) 491 (561 ) Comprehensive income (loss) 168 (334 ) (142 ) 27 Dividend on preferred stock 7 7 7 7 Comprehensive income (loss) available (attributable) to common shareholders $ 161 $ (341 ) $ (149 ) $ 20 Weighted average number of common shares outstanding-basic and diluted 352.8 352.1 347.8 341.6 Net income (loss) per common share - basic and diluted $ (0.73 ) $ 1.43 $ (1.84 ) $ 1.70 Comprehensive income (loss) per common share - basic and diluted $ 0.46 $ (0.97 ) $ (0.43 ) $ 0.06 Dividends declared per common share $ 0.66 $ 0.62 $ 0.60 $ 0.60

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Event	Subsequent Events On each of January 12, 2017 and February 14, 2017 , our Board of Directors declared a monthly dividend of $0.18 per common share, payable on February 8, 2017 and March 8, 2017 , respectively, to common stockholders of record as of January 31, 2017 and February 28, 2017 , respectively. On February 1, 2017, we entered into sales agreements with underwriters to publicly offer and sell shares of our common stock, from time-to-time, through publicly negotiated and/or at-the-market transactions, up to an aggregate offering amount of $750 million .

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Basis of Presentation and Significant Accounting Policies [Text Block]	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, Policy [Policy Text Block]	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.
Earnings Per Share, Policy [Policy Text Block]	Earnings per Share Basic earnings per share ("EPS") is computed by dividing net income (loss) available (attributable) to common stockholders by the weighted average number of common shares outstanding during the period. Diluted EPS assumes the conversion, exercise or issuance of all potential common stock equivalents unless the effect is to reduce a loss or increase the income per share.
Comprehensive Income, Policy [Policy Text Block]	Accumulated Other Comprehensive Income (Loss) Accounting Standards Codification ("ASC") Topic 220, Comprehensive Income , divides comprehensive income into net income and other comprehensive income (loss) ("OCI"), which includes unrealized gains and losses on securities classified as available-for-sale and unrealized gains and losses on derivative financial instruments that are designated and qualify for cash flow hedge accounting under ASC Topic 815, Derivatives and Hedging ("ASC 815"). During fiscal year 2011, we discontinued designating our derivative financial instruments, principally interest rate swaps, as cash flow hedges. For further information regarding our discontinuation of cash flow hedge accounting, see Derivatives Instruments below and Note 5.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents Cash and cash equivalents consist of unrestricted demand deposits and highly liquid investments with original maturities of three months or less. Cash and cash equivalents are carried at cost, which approximates fair value.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash and Cash Equivalents Restricted cash and cash equivalents includes cash and cash equivalents pledged as collateral for clearing and executing trades, repurchase agreements and other borrowings, and interest rate swaps and other derivative instruments. Restricted cash and cash equivalents are carried at cost, which approximates fair value.
Federal Home Loan Bank Advances [Policy Text Block]	Federal Home Loan Bank Advances Federal Home Loan Bank ("FHLB") advances are secured loans from the FHLB of Des Moines used to finance the acquisitions of investment securities. We account for FHLB advances as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest, as specified in the respective transactions. In April 2015, our wholly-owned captive insurance subsidiary, Old Georgetown Insurance Co., LLC ("OGI"), was approved as a member of the FHLB of Des Moines. The FHLBs provide a variety of products and services to their members, including short and long-term secured loans. In January 2016, the Federal Housing Finance Agency released its final rule on changes to regulations concerning FHLB membership criteria. The final rule terminated OGI's FHLB membership and required repayment of all advances at the earlier of their contractual maturity dates or a one year period after the effective date of the final rule that concluded in February 2017. Interest rates under our FHLB advances generally correspond to the FHLB's Member Option Variable Rate or to one or three month LIBOR plus or minus a fixed spread. The fair value of our FHLB advances is assumed to equal cost as the interest rates are considered to be at market.
Reverse Repurchase Agreements Policy [Policy Text Block]	Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We from time to time borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivatives 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. Our reverse repurchase agreements generally mature daily. The fair value of our reverse repurchase agreements is assumed to equal cost as the interest rates are generally reset daily.
Income Tax Disclosure [Text Block]	Income Taxes We elected to be taxed as a REIT under the provisions of the Internal Revenue Code and the corresponding provisions of state law, commencing with our initial tax year ended December 31, 2008. In order to continue to qualify as a REIT, we must annually distribute, in a timely manner to our stockholders, at least 90% of our taxable ordinary income, amongst other conditions. A REIT is generally not subject to U.S. federal and state corporate income tax on its earnings to the extent that it distributes its annual taxable net income to its stockholders and as long as certain asset, income and stock ownership tests are met. We operate in a manner that will allow us to be taxed as a REIT. As permitted by the Internal Revenue Code, a REIT can designate dividends paid in the subsequent year as dividends of the current year if those dividends are both declared by the extended due date of the REIT's federal income tax return and paid to stockholders by the last day of the subsequent year; however, we may still be subject to a non-deductible 4% excise tax if the actual amount distributed to our stockholders in a calendar year is less than the minimum amount specified under federal tax laws. We have a wholly-owned subsidiary for which we elected to treat as taxable REIT subsidiary. As such it is subject to federal and state income tax based on its taxable income. All other subsidiaries are disregarded entities for U.S. federal income tax purposes. As such, their assets, liabilities and income are generally treated as our assets, liabilities and income for purposes of U.S. federal and state corporate income taxes. We evaluate uncertain income tax positions, if any, in accordance with ASC Topic 740, Income Taxes ("ASC 740"). To the extent we incur interest and/or penalties in connection with our tax obligations, such amounts shall be classified as income tax expense on our consolidated statements of operations. Income Taxes As of December 31, 2016 , we have distributed all of our estimated taxable income for fiscal year 2016 . Accordingly, we do not expect to incur an income tax liability on our 2016 taxable income. For fiscal years 2015 and 2014, we distributed all of our taxable income within the 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, 2016 , 2015 and 2014. Our tax returns for tax years 2013 and forward are open to examination by the IRS. In the event that we incur income tax related interest and penalties, our policy is to classify them as a component of provision for income taxes.
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 2014-09, Revenue from Contracts with Customers (Topic 606): ASU 2014-09 is a comprehensive revenue recognition standard that supersedes virtually all existing revenue guidance under U.S. GAAP. The standard’s core principle is that an entity will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. Revenue recognition with respect to financial instruments is not within the scope of ASU 2014-09 and, therefore, it is not expected to have a significant impact on our consolidated financial statements. ASU 2014-09 is effective on January 1, 2018. ASU 2016-09, Compensation — Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting: ASU 2016-09 simplifies several aspects of the accounting for employee share-based payment transactions for both public and nonpublic entities, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. The ASU is effective on January 1, 2017, with early adoption permitted. We early adopted ASU 2016-09 during fiscal year 2016, which did not have a significant impact on our consolidated financial statements. ASU 2016-13, Financial Instruments - Credit Losses (Topic 606): ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. Allowances for credit losses on available-for-sale debt securities will be recognized, rather than direct reductions in the amortized cost of the investments. 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, with early adoption permitted for annual periods, and interim periods within those annual periods, beginning on or after December 15, 2018. ASU 2016-13 is not expected to have a significant impact on our consolidated financial statements. ASU 2016-18, Statement of Cash Flows (Topic 230) - Restricted Cash: ASU 2016-18 requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 will be effective on January 1, 2018 and is not expected to have a significant impact on our consolidated financial statements.
Investment Securities	Investment Securities We primarily invest in Agency RMBS. Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") for which the principal and interest payments are guaranteed by a U.S. Government-sponsored enterprise, such as the Federal National Mortgage Association ("Fannie Mae") and the Federal Home Loan Mortgage Corporation ("Freddie Mac"), or by a U.S. Government agency, such as the Government National Mortgage Association ("Ginnie Mae") (collectively referred to as "GSEs"). Interest-only and inverse interest-only securities (together referred to as "interest-only securities") represent the right to receive a specified proportion of the contractual interest flows of specific Agency CMO securities. Principal-only securities represent the right to receive the contractual principal flows of specific Agency CMO securities. CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third party market participants, that 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 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 are able to 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. REIT equity securities represent investments in the common stock of other publicly traded mortgage REITs that invest primarily in Agency RMBS. 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 for such securities pursuant to ASC Topic 825, Financial Instruments . We report securities classified as trading or available-for-sale or for which if we elected the fair value option at fair value, while securities classified as held-to-maturity are reported at amortized cost. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income (loss) ("OCI"). Unrealized gains and losses on securities classified as trading or for which we elected the fair value option are reflected in net income through other gain (loss) during the period in which they occur. We may sell any of our securities as part of our overall management of our investment portfolio. Accordingly, unless we elect the fair value option, we typically designate our investment securities as available-for-sale. Investments in REIT equity securities are designated as trading securities. 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. We have elected the fair value option to account for CRT securities, interest and principal-only securities and CMBS as this election simplifies the accounting for such securities. Effective January 1, 2017, we elected the fair value option for future purchases of all investment securities, including Agency RMBS and non-Agency MBS. In our view, this election will more appropriately reflect the result of our operations for a particular reporting period, as the fair value changes for these financial assets will be presented in a manner consistent with the presentation and timing of the fair value changes of our hedging instruments. We are not permitted to change the designation of available-for-sale securities acquired prior to January 1, 2017, accordingly, such securities will continue to be classified as available-for-sale securities until such time as we receive full repayment or we dispose of the security. We estimate the fair value of Agency RMBS, non-Agency MBS and CRT securities based on a market approach using "Level 2" inputs from third-party pricing services and non-binding dealer quotes derived from common market pricing methods. Such methods incorporate, but are not limited to, reported trades and executable bid and asked prices for similar securities, benchmark interest rate curves, such as the spread to the U.S. Treasury rate and interest rate swap curves, convexity, duration and the underlying characteristics of the particular security, including coupon, periodic and life caps, rate reset period, issuer, additional credit support and expected life of the security. We estimate the fair value of REIT equity securities based on a market approach using "Level 1" inputs based on quoted market prices. Refer to Note 7 for further discussion of fair value measurements. We evaluate our investments designated as available-for-sale for other-than-temporary impairment ("OTTI") on at least a quarterly basis. 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. However, with respect to the first condition, since the liquidity of the Agency securities market allows us to obtain competitive bids and execute on a sale transaction typically within a day of making the decision to sell a security, we generally do not make decisions to sell specific mortgage securities until shortly prior to initiating a sell order. In some instances, we may sell specific Agency securities by delivering the securities into existing short "to-be-announced" ("TBA") contracts. TBA market conventions require the identification of the specific securities to be delivered no later than 48 hours prior to settlement. If we settle a short TBA contract through the delivery of securities, we will generally identify the specific securities to be delivered within one to two days before the 48-hour deadline. 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. However, in evaluating if the third condition exists, our investments in Agency securities typically would not have a credit component since the principal and interest are guaranteed by a GSE and, therefore, any unrealized loss is not the result of a credit loss. In addition, since unrealized gains and losses for securities designated as available-for-sale are recognized in OCI, any impairment loss for non-credit components is already recognized in OCI. We did not recognize any OTTI charges on our investment securities for fiscal years 2016 , 2015 or 2014.
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 estimates prepayment speeds using models that incorporate the forward yield curve, current mortgage rates and 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 prepayment speeds estimated by the third-party service and, based on our judgment, we may make adjustments to its estimates. Actual and anticipated prepayment experience is reviewed quarterly and effective yields are recalculated when differences arise between (i) our previously estimated future prepayments and (ii) the actual prepayments to date plus our currently estimated future prepayments. If the actual and estimated future prepayment experience differs from our prior estimate of prepayments, we are required to record an adjustment in the current period to the amortization or accretion of premiums and discounts for the cumulative difference in the effective yield 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 about interest rates, prepayment rates, the timing and amount of credit losses, and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment as adjusted for credit impairment, 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 ("ASC 860"), we account for repurchase transactions as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest, as specified in the respective transactions. Our repurchase agreements typically have maturities of less than one year, but may extend up to five years or more. Interest rates under our repurchase agreements generally correspond to one, three or six month LIBOR 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 risk. 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 principal instruments that we use are interest rate swaps and options to enter into interest rate swaps ("swaptions"). We also utilize U.S. Treasury securities and U.S. Treasury futures contracts, primarily through short sales, and forward contracts for the purchase or sale of Agency RMBS securities on a generic pool basis in the "to-be-announced" market ("TBA securities") and on a specified pool basis. We may also purchase or write put or call options on TBA securities and utilize other types of derivative instruments to hedge a portion of our risk. We also enter into TBA contracts as a means of investing in and financing Agency securities (thereby increasing our "at risk" leverage) or as a means of disposing of or reducing our exposure to Agency securities (thereby reducing our "at risk" leverage). Under TBA contracts, we agree to purchase or sell, for future delivery, Agency securities with certain principal and interest terms and certain types of collateral, but the particular Agency securities to be delivered are not identified until shortly before the TBA settlement date. We may also choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting short or long position (referred to as a "pair off"), net settling the paired off positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date. This transaction is commonly referred to as a "dollar roll." The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to Agency securities for settlement in the current month. This difference (or discount) is referred to as the "price drop." The price drop is the economic equivalent of net interest carry income on the underlying Agency securities over the roll period (interest income less implied financing cost) and is commonly referred to as "dollar roll income/loss." Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. 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. 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 in the event that the counterparties to these instruments fail to perform their obligations under the contracts. We attempt to minimize this risk by limiting our counterparties to major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Discontinuation of hedge accounting for interest rate swap agreements Prior to fiscal year 2011, we entered into interest rate swap agreements typically with the intention of qualifying for hedge accounting under ASC 815. However, during fiscal year 2011, we elected to discontinue hedge accounting for our interest rate swaps. Upon discontinuation of hedge accounting, the net deferred loss related to our de-designated interest rate swaps remained in accumulated OCI and has been reclassified from accumulated OCI into interest expense on a straight-line basis over the remaining term of each interest rate swap through December 2016. Interest rate swap agreements We use interest rate swaps to hedge the variable cash flows associated with borrowings made under our repurchase agreement facilities. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate based on one, three or six-month LIBOR ("payer swaps") with terms up to 20 years. The floating rate we receive under our swap agreements has the effect of offsetting the repricing characteristics of our repurchase agreements and cash flows on such liabilities. Our swap agreements are privately negotiated in the over−the−counter ("OTC") market. Swap agreements entered into subsequent to May 2013 are centrally cleared through a registered commodities exchange ("centrally cleared swaps"). We estimate the fair value of our centrally cleared interest rate swaps using the daily settlement price determined by the respective exchange. Centrally cleared swaps are valued by the exchange using a pricing model that references the underlying rates including the overnight index swap rate and LIBOR forward rate to produce the daily settlement price. We estimate the fair value of our "non-centrally cleared" swaps using a combination of inputs from counterparty and third-party pricing models to estimate the net present value of the future cash flows using the forward interest rate yield curve in effect as of the end of the measurement period. We also incorporate 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 consider 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 generally 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 swaption agreements typically provide us the option to enter into a pay-fixed rate interest rate swap, which we refer as "payer swaptions." We may also enter into swaption agreements that provide us the option to enter into a receive-fixed interest rate swap, which we refer to as "receiver swaptions." The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. The premium is valued at an amount equal to the fair value of the swaption that would have the effect of closing the position adjusted for nonperformance risk, if any. The difference between the premium 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 received and the premium paid. Our interest rate swaption agreements are privately negotiated in the OTC market and are not subject to central clearing. 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. TBA securities A TBA security is a forward contract for the purchase ("long position") or sale ("short position") of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS delivered into the contract upon the settlement date, published each month by the Securities Industry and Financial Markets Association, are not known at the time of the transaction. We may enter into TBA contracts as a means of hedging against short-term changes in interest rates. We may also enter into TBA contracts as a means of acquiring or disposing of Agency securities and utilize TBA dollar roll transactions to finance Agency RMBS purchases. 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 take physical delivery of the Agency security upon settlement of the contract. We account for TBA dollar roll transactions as a series of derivative transactions. Gains, losses and dollar roll income associated with our TBA contracts and dollar roll transactions are recognized in our consolidated statements of comprehensive income in gain (loss) on derivative instruments and other securities, net. We estimate the fair value of TBA securities based on similar methods used to value our Agency RMBS securities. U.S. Treasury securities We purchase and sell short U.S. Treasury securities and U.S. Treasury futures contracts to help mitigate the potential impact of changes in interest rates on the performance of our portfolio. We borrow securities to cover short sales of U.S. Treasury securities under reverse repurchase agreements. 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 borrowed securities as of the reporting date. Gains and losses associated with purchases and short sales of 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.
Variable Interest Entity Disclosure [Text Block]	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. Further, ASC 810 requires a qualitative assessment to determine the primary beneficiary of a VIE and ongoing assessments of whether an enterprise is the primary beneficiary of a VIE as well as additional disclosures for entities that have variable interests in VIEs. We have entered into transactions involving CMO trusts, which are VIEs. We will consolidate a CMO trust if we are the CMO trust's primary beneficiary; that is, if we have a variable interest that provides us with a controlling financial interest in the CMO trust. An entity is deemed to have a controlling financial interest if the entity has the power to direct the activities of a VIE that most significantly impact the VIE's economic performance and the obligation to absorb losses of or right to receive benefits from the VIE that could potentially be significant to the VIE. As part of the qualitative assessment in determining if we have a controlling financial interest, we evaluate whether we control the selection of financial assets transferred to the CMO trust. For each of our consolidated CMO trusts we controlled the selection of the Agency RMBS transferred from our investment portfolio to an investment bank in exchange for cash proceeds and at the same time entered into a commitment with the investment bank to purchase to-be-issued securities collateralized by the Agency RMBS transferred, which resulted in our consolidation of the CMO trusts. Agency RMBS transferred to consolidated VIEs are reported on our consolidated balance sheets in Agency securities transferred to consolidated VIEs, at fair value and can only be used to settle the obligations of each respective VIE. We elected the option to account for the consolidated debt at fair value, with changes in fair value reflected in earnings during the period in which they occur, because 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 transferred to consolidated VIEs, less the fair value of our retained interests, which are measured on a market approach using "Level 2" inputs from third-party pricing services and dealer quotes. The fair value of the Agency RMBS transferred to the consolidated VIEs and the fair value of our retained interests are based on more observable inputs than inputs used to independently determine the value of our consolidated debt.
Contingencies Disclosure [Text Block]	Loss Contingencies We evaluate the existence of any pending or threatened litigation or other potential claims against the Company in accordance with ASC Topic 450, Contingencies, which requires that we assess the likelihood and range of potential outcomes of any such matters. We are the defendant in two stockholder derivative lawsuits alleging that certain of our current and former directors and officers breached fiduciary duties and wasted corporate assets in connection with past renewals of the management agreement with our former external Manager and the internalization of our management, which occurred on July 1, 2016. Although the outcomes of these cases cannot be predicted with certainty, we do not believe that these cases have merit or will result in a material liability and, as of December 31, 2016, we did not accrue a loss contingency related to these matters.

Summary of Significant Accoun23

Summary of Significant Accounting Policies Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Derivatives, Policy [Policy Text Block]	Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate, prepayment, extension and liquidity risk. 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 principal instruments that we use are interest rate swaps and options to enter into interest rate swaps ("swaptions"). We also utilize U.S. Treasury securities and U.S. Treasury futures contracts, primarily through short sales, and forward contracts for the purchase or sale of Agency RMBS securities on a generic pool basis in the "to-be-announced" market ("TBA securities") and on a specified pool basis. We may also purchase or write put or call options on TBA securities and utilize other types of derivative instruments to hedge a portion of our risk. We also enter into TBA contracts as a means of investing in and financing Agency securities (thereby increasing our "at risk" leverage) or as a means of disposing of or reducing our exposure to Agency securities (thereby reducing our "at risk" leverage). Under TBA contracts, we agree to purchase or sell, for future delivery, Agency securities with certain principal and interest terms and certain types of collateral, but the particular Agency securities to be delivered are not identified until shortly before the TBA settlement date. We may also choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting short or long position (referred to as a "pair off"), net settling the paired off positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date. This transaction is commonly referred to as a "dollar roll." The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to Agency securities for settlement in the current month. This difference (or discount) is referred to as the "price drop." The price drop is the economic equivalent of net interest carry income on the underlying Agency securities over the roll period (interest income less implied financing cost) and is commonly referred to as "dollar roll income/loss." Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. 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. 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 in the event that the counterparties to these instruments fail to perform their obligations under the contracts. We attempt to minimize this risk by limiting our counterparties to major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Discontinuation of hedge accounting for interest rate swap agreements Prior to fiscal year 2011, we entered into interest rate swap agreements typically with the intention of qualifying for hedge accounting under ASC 815. However, during fiscal year 2011, we elected to discontinue hedge accounting for our interest rate swaps. Upon discontinuation of hedge accounting, the net deferred loss related to our de-designated interest rate swaps remained in accumulated OCI and has been reclassified from accumulated OCI into interest expense on a straight-line basis over the remaining term of each interest rate swap through December 2016. Interest rate swap agreements We use interest rate swaps to hedge the variable cash flows associated with borrowings made under our repurchase agreement facilities. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate based on one, three or six-month LIBOR ("payer swaps") with terms up to 20 years. The floating rate we receive under our swap agreements has the effect of offsetting the repricing characteristics of our repurchase agreements and cash flows on such liabilities. Our swap agreements are privately negotiated in the over−the−counter ("OTC") market. Swap agreements entered into subsequent to May 2013 are centrally cleared through a registered commodities exchange ("centrally cleared swaps"). We estimate the fair value of our centrally cleared interest rate swaps using the daily settlement price determined by the respective exchange. Centrally cleared swaps are valued by the exchange using a pricing model that references the underlying rates including the overnight index swap rate and LIBOR forward rate to produce the daily settlement price. We estimate the fair value of our "non-centrally cleared" swaps using a combination of inputs from counterparty and third-party pricing models to estimate the net present value of the future cash flows using the forward interest rate yield curve in effect as of the end of the measurement period. We also incorporate 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 consider 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 generally 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 swaption agreements typically provide us the option to enter into a pay-fixed rate interest rate swap, which we refer as "payer swaptions." We may also enter into swaption agreements that provide us the option to enter into a receive-fixed interest rate swap, which we refer to as "receiver swaptions." The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. The premium is valued at an amount equal to the fair value of the swaption that would have the effect of closing the position adjusted for nonperformance risk, if any. The difference between the premium 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 received and the premium paid. Our interest rate swaption agreements are privately negotiated in the OTC market and are not subject to central clearing. 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. TBA securities A TBA security is a forward contract for the purchase ("long position") or sale ("short position") of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS delivered into the contract upon the settlement date, published each month by the Securities Industry and Financial Markets Association, are not known at the time of the transaction. We may enter into TBA contracts as a means of hedging against short-term changes in interest rates. We may also enter into TBA contracts as a means of acquiring or disposing of Agency securities and utilize TBA dollar roll transactions to finance Agency RMBS purchases. 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 take physical delivery of the Agency security upon settlement of the contract. We account for TBA dollar roll transactions as a series of derivative transactions. Gains, losses and dollar roll income associated with our TBA contracts and dollar roll transactions are recognized in our consolidated statements of comprehensive income in gain (loss) on derivative instruments and other securities, net. We estimate the fair value of TBA securities based on similar methods used to value our Agency RMBS securities. U.S. Treasury securities We purchase and sell short U.S. Treasury securities and U.S. Treasury futures contracts to help mitigate the potential impact of changes in interest rates on the performance of our portfolio. We borrow securities to cover short sales of U.S. Treasury securities under reverse repurchase agreements. 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 borrowed securities as of the reporting date. Gains and losses associated with purchases and short sales of 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 We primarily invest in Agency RMBS. Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") for which the principal and interest payments are guaranteed by a U.S. Government-sponsored enterprise, such as the Federal National Mortgage Association ("Fannie Mae") and the Federal Home Loan Mortgage Corporation ("Freddie Mac"), or by a U.S. Government agency, such as the Government National Mortgage Association ("Ginnie Mae") (collectively referred to as "GSEs"). Interest-only and inverse interest-only securities (together referred to as "interest-only securities") represent the right to receive a specified proportion of the contractual interest flows of specific Agency CMO securities. Principal-only securities represent the right to receive the contractual principal flows of specific Agency CMO securities. CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third party market participants, that 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 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 are able to 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. REIT equity securities represent investments in the common stock of other publicly traded mortgage REITs that invest primarily in Agency RMBS. 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 for such securities pursuant to ASC Topic 825, Financial Instruments . We report securities classified as trading or available-for-sale or for which if we elected the fair value option at fair value, while securities classified as held-to-maturity are reported at amortized cost. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income (loss) ("OCI"). Unrealized gains and losses on securities classified as trading or for which we elected the fair value option are reflected in net income through other gain (loss) during the period in which they occur. We may sell any of our securities as part of our overall management of our investment portfolio. Accordingly, unless we elect the fair value option, we typically designate our investment securities as available-for-sale. Investments in REIT equity securities are designated as trading securities. 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. We have elected the fair value option to account for CRT securities, interest and principal-only securities and CMBS as this election simplifies the accounting for such securities. Effective January 1, 2017, we elected the fair value option for future purchases of all investment securities, including Agency RMBS and non-Agency MBS. In our view, this election will more appropriately reflect the result of our operations for a particular reporting period, as the fair value changes for these financial assets will be presented in a manner consistent with the presentation and timing of the fair value changes of our hedging instruments. We are not permitted to change the designation of available-for-sale securities acquired prior to January 1, 2017, accordingly, such securities will continue to be classified as available-for-sale securities until such time as we receive full repayment or we dispose of the security. We estimate the fair value of Agency RMBS, non-Agency MBS and CRT securities based on a market approach using "Level 2" inputs from third-party pricing services and non-binding dealer quotes derived from common market pricing methods. Such methods incorporate, but are not limited to, reported trades and executable bid and asked prices for similar securities, benchmark interest rate curves, such as the spread to the U.S. Treasury rate and interest rate swap curves, convexity, duration and the underlying characteristics of the particular security, including coupon, periodic and life caps, rate reset period, issuer, additional credit support and expected life of the security. We estimate the fair value of REIT equity securities based on a market approach using "Level 1" inputs based on quoted market prices. Refer to Note 7 for further discussion of fair value measurements. We evaluate our investments designated as available-for-sale for other-than-temporary impairment ("OTTI") on at least a quarterly basis. 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. However, with respect to the first condition, since the liquidity of the Agency securities market allows us to obtain competitive bids and execute on a sale transaction typically within a day of making the decision to sell a security, we generally do not make decisions to sell specific mortgage securities until shortly prior to initiating a sell order. In some instances, we may sell specific Agency securities by delivering the securities into existing short "to-be-announced" ("TBA") contracts. TBA market conventions require the identification of the specific securities to be delivered no later than 48 hours prior to settlement. If we settle a short TBA contract through the delivery of securities, we will generally identify the specific securities to be delivered within one to two days before the 48-hour deadline. 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. However, in evaluating if the third condition exists, our investments in Agency securities typically would not have a credit component since the principal and interest are guaranteed by a GSE and, therefore, any unrealized loss is not the result of a credit loss. In addition, since unrealized gains and losses for securities designated as available-for-sale are recognized in OCI, any impairment loss for non-credit components is already recognized in OCI. We did not recognize any OTTI charges on our investment securities for fiscal years 2016 , 2015 or 2014.
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 estimates prepayment speeds using models that incorporate the forward yield curve, current mortgage rates and 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 prepayment speeds estimated by the third-party service and, based on our judgment, we may make adjustments to its estimates. Actual and anticipated prepayment experience is reviewed quarterly and effective yields are recalculated when differences arise between (i) our previously estimated future prepayments and (ii) the actual prepayments to date plus our currently estimated future prepayments. If the actual and estimated future prepayment experience differs from our prior estimate of prepayments, we are required to record an adjustment in the current period to the amortization or accretion of premiums and discounts for the cumulative difference in the effective yield 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 about interest rates, prepayment rates, the timing and amount of credit losses, and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment as adjusted for credit impairment, if any.
Goodwill and Intangible Assets, Policy [Policy Text Block]	Goodwill and Other Intangible Assets, Net Goodwill is the cost of an acquisition in excess of the fair value of identified assets acquired and liabilities assumed. Goodwill is recorded as an asset on our balance sheet. Acquired intangible assets that do not meet the criteria for recognition as a separate asset are included in goodwill. Goodwill is not subject to amortization but must be tested for impairment at least annually. Intangible assets meeting the criteria for recognition as separate assets are recorded at their respective fair market values at the date of acquisition. Intangible assets with an estimated useful life are amortized over their expected useful life. As of December 31, 2016 , we had $526 million of goodwill and $28 million of other intangible assets, net of accumulated amortization, reported in goodwill and other intangible assets, net in our accompanying consolidated balance sheets related to our acquisition of AMM on July 1, 2016 (see Note 12 for further details). We test goodwill for impairment on an annual basis 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 impairment test for goodwill utilizes a two-step approach whereby we compare the carrying value of the identified reporting unit comprising the goodwill to its fair value. If the carrying value of the reporting unit is greater than its fair value, the second step is performed, where the implied fair value of goodwill is determined and compared to its carrying value. An impairment charge is recognized to the extent the carrying amount of goodwill exceeds its fair value.

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Securities by Credit Rating [Table Text Block]	As of December 31, 2016 and 2015, our investments in non-Agency securities had the following credit ratings: December 31, 2016 December 31, 2015 Non-Agency Security Credit Ratings 1 CRT RMBS CMBS CRT RMBS CMBS AAA $ — $ 99 $ — $ — $ 113 $ — BBB — — 23 — — — B 164 2 — — — — Total $ 164 $ 101 $ 23 $ — $ 113 $ — ________________________ 1. Represents the lowest of Standard and Poor's ("S&P"), Moody's and Fitch credit ratings, stated in terms of the S&P equivalent rating as of each date.
Available-for-sale Securities [Table Text Block]	December 31, 2016 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 34,244 $ 10,008 $ 44 $ 101 $ — $ — $ 44,397 Unamortized discount (43 ) (3 ) — — — — (46 ) Unamortized premium 1,518 544 — 1 — — 2,063 Amortized cost 35,719 10,549 44 102 — — 46,414 Gross unrealized gains 176 48 1 — — — 225 Gross unrealized losses (442 ) (179 ) — (1 ) — — (622 ) Total available-for-sale securities, at fair value 35,453 10,418 45 101 — — 46,017 Securities remeasured at fair value through earnings: Par value 1 171 — — — 24 157 352 Unamortized discount (35 ) — — — (1 ) — (36 ) Unamortized premium 118 14 — — — 4 136 Amortized cost 254 14 — — 23 161 452 Gross unrealized gains 28 3 — — — 3 34 Gross unrealized losses (3 ) (1 ) — — — — (4 ) Total securities remeasured at fair value through earnings 279 16 — — 23 164 482 Total securities, at fair value $ 35,732 $ 10,434 $ 45 $ 101 $ 23 $ 164 $ 46,499 Weighted average coupon as of December 31, 2016 3.59 % 3.67 % 2.75 % 3.42 % 6.55 % 5.25 % 3.61 % Weighted average yield as of December 31, 2016 2 2.77 % 2.72 % 2.00 % 3.27 % 7.54 % 6.28 % 2.77 % ________________________ 1. Par value amount excludes the underlying unamortized principal balance ("UPB") of interest-only securities of $0.9 billion as of December 31, 2016 . 2. Incorporates a weighted average future constant prepayment rate assumption of 8% based on forward rates as of December 31, 2016 . December 31, 2015 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS Total Available-for-sale securities: Par value $ 39,205 $ 10,575 $ 62 $ 113 $ 49,955 Unamortized discount (32 ) (4 ) — — (36 ) Unamortized premium 1,707 519 1 1 2,228 Amortized cost 40,880 11,090 63 114 52,147 Gross unrealized gains 286 80 2 — 368 Gross unrealized losses (283 ) (111 ) — (1 ) (395 ) Total available-for-sale securities, at fair value 40,883 11,059 65 113 52,120 Securities remeasured at fair value through earnings: Par value 1 208 — — — 208 Unamortized discount (42 ) — — — (42 ) Unamortized premium 132 19 — — 151 Amortized cost 298 19 — — 317 Gross unrealized gains 35 4 — — 39 Gross unrealized losses (2 ) (1 ) — — (3 ) Total securities remeasured at fair value through earnings 331 22 — — 353 Total securities, at fair value $ 41,214 $ 11,081 $ 65 $ 113 $ 52,473 Weighted average coupon as of December 31, 2015 3.62 % 3.69 % 3.18 % 3.50 % 3.63 % Weighted average yield as of December 31, 2015 2 2.79 % 2.77 % 1.97 % 3.33 % 2.78 % ________________________ 1. Par value amount excludes the UPB of interest-only securities of $1.0 billion as of December 31, 2015 . 2. Incorporates a weighted average future constant prepayment rate assumption of 8% based on forward rates as of December 31, 2015 .
Components of Investment Securities	The following tables summarize our investment securities as of December 31, 2016 and 2015 (dollars in millions): December 31, 2016 Investment Securities Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Agency RMBS: Fixed rate $ 45,145 $ 210 $ (619 ) $ 44,736 Adjustable rate 371 8 — 379 CMO 796 7 (2 ) 801 Interest-only and principal-only strips 268 31 (4 ) 295 Total Agency RMBS 46,580 256 (625 ) 46,211 Non-Agency RMBS 102 — (1 ) 101 CMBS 23 — — 23 CRT securities 161 3 — 164 Total investment securities $ 46,866 $ 259 $ (626 ) $ 46,499 December 31, 2015 Investments Securities Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Agency RMBS: Fixed rate $ 50,576 $ 339 $ (393 ) $ 50,522 Adjustable rate 484 11 — 495 CMO 973 18 (1 ) 990 Interest-only and principal-only strips 317 39 (3 ) 353 Total Agency RMBS 52,350 407 (397 ) 52,360 Non-Agency RMBS 114 — (1 ) 113 Total investment securities $ 52,464 $ 407 $ (398 ) $ 52,473
Summary Of Agency Securities Estimated Weighted Average Life Classifications	The following table summarizes our investments classified as available-for-sale as of December 31, 2016 and 2015 according to their estimated weighted average life classification (dollars in millions): December 31, 2016 December 31, 2015 Estimated Weighted Average Life of Securities Classified as Available-for-Sale Fair Value Amortized Cost Weighted Average Coupon Weighted Average Yield Fair Value Amortized Cost Weighted Average Coupon Weighted Average Yield ≥ 1 year and ≤ 3 years $ 414 $ 410 3.99% 2.52% $ 167 $ 163 4.02% 2.66% > 3 years and ≤ 5 years 13,534 13,449 3.26% 2.40% 17,497 17,343 3.27% 2.40% > 5 years and ≤10 years 30,226 30,713 3.65% 2.86% 34,206 34,391 3.67% 2.93% > 10 years 1,843 1,842 3.02% 3.07% 250 250 3.56% 3.08% Total $ 46,017 $ 46,414 3.52% 2.73% $ 52,120 $ 52,147 3.54% 2.75%
Summary of Continuous Unrealized Loss Position of Available for Sale Securities	The following table presents the gross unrealized loss and fair values of our available-for-sale securities by length of time that such securities have been in a continuous unrealized loss position as of December 31, 2016 and 2015 (in millions): Unrealized Loss Position For Less than 12 Months 12 Months or More Total Securities Classified as Available-for-Sale Estimated Fair Value Unrealized Loss Estimated Fair Value Unrealized Loss Estimated Fair Value Unrealized Loss December 31, 2016 $ 28,397 $ (554 ) $ 1,719 $ (68 ) $ 30,116 $ (622 ) December 31, 2015 $ 24,035 $ (200 ) $ 6,793 $ (195 ) $ 30,828 $ (395 )
Summary of Net Gain from Sale of Agency Securities	The following table is a summary of our net gain (loss) from the sale of securities classified as available-for-sale for fiscal years 2016 , 2015 and 2014 (in millions). Please refer to Note 8 for a summary of changes in accumulated OCI for the same periods . Fiscal Year Securities Classified as Available-for-Sale 2016 2015 2014 RMBS sold, at cost $ (17,907 ) $ (27,578 ) $ (30,123 ) Proceeds from RMBS sold 1 18,016 27,555 30,174 Net gain (loss) on sale of RMBS $ 109 $ (23 ) $ 51 Gross gain on sale of RMBS $ 123 $ 98 $ 172 Gross loss on sale of RMBS (14 ) (121 ) (121 ) Net gain (loss) on sale of RMBS $ 109 $ (23 ) $ 51 ________________________ 1. Proceeds include cash received during the period, plus receivable for RMBS sold during the period as of period end.

Repurchase Agreements and Oth25

Repurchase Agreements and Other Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Repurchase Agreements [Abstract]
Schedule of Borrowings under Repurchase Agreements and Weighted Average Interest Rates	The following table summarizes our borrowings under repurchase agreements by their remaining maturities as of December 31, 2016 and 2015 (dollars in millions): December 31, 2016 December 31, 2015 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 $ 17,481 0.90 % 11 $ 17,579 0.54 % 14 > 1 to ≤ 3 months 10,011 0.93 % 55 14,283 0.64 % 58 > 3 to ≤ 6 months 2,030 1.02 % 136 3,154 0.61 % 121 > 6 to ≤ 9 months 1,270 0.98 % 214 589 0.65 % 199 > 9 to ≤ 12 months 1,566 1.08 % 299 1,201 0.65 % 307 > 12 to ≤ 24 months 1,203 1.28 % 538 1,473 0.73 % 600 > 24 to ≤ 36 months 1,300 1.36 % 865 650 0.81 % 901 > 36 to ≤ 48 months 2,200 1.32 % 1,168 1,300 0.86 % 1,231 > 48 to < 60 months 625 1.38 % 1,506 1,500 0.76 % 1,477 Total Agency repo 37,686 0.98 % 187 41,729 0.61 % 173 U.S. Treasury repo: 1 day — — % — 25 — % 1 > 1 day to ≤ 1 month 172 (0.30 )% 17 — — % — Total $ 37,858 0.98 % 186 $ 41,754 0.61 % 173
Schedule of Federal Home Loan Bank Advances and Weighted Average Interest Rates [Table Text Block]	As of December 31, 2016 and 2015 , we had $3.0 billion and $3.8 billion , respectively, of outstanding secured FHLB advances, with a weighted average borrowing rate of 0.73% and 0.53% , respectively, and a weighted average remaining term to maturity of 28 and 141 days, respectively, consisting of 30 day and longer-term floating rate advances: December 31, 2016 December 31, 2015 Remaining Maturity FHLB Advances Weighted Weighted FHLB Advances Weighted Weighted ≤ 1 month $ 1,353 0.67 % 7 $ 1,952 0.47 % 14 > 1 to ≤ 3 months 1,684 0.77 % 44 681 0.60 % 84 13 months — — % — 1,120 0.58 % 397 Total FHLB advances $ 3,037 0.73 % 28 $ 3,753 0.53 % 141

Derivative and Other Hedging 26

Derivative and Other Hedging Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Derivative [Line Items]
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, 2016 and 2015 (in millions): December 31, Derivative and Other Hedging Instruments Balance Sheet Location 2016 2015 Interest rate swaps Derivative assets, at fair value $ 321 $ 31 Swaptions Derivative assets, at fair value 22 17 TBA securities Derivative assets, at fair value 4 29 U.S. Treasury futures - short Derivative assets, at fair value 8 4 Total derivative assets, at fair value $ 355 $ 81 Interest rate swaps Derivative liabilities, at fair value $ (105 ) $ (920 ) TBA securities Derivative liabilities, at fair value (151 ) (15 ) Total derivative liabilities, at fair value $ (256 ) $ (935 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ 182 $ 25 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (7,636 ) (1,696 ) Total U.S. Treasury securities, net at fair value $ (7,454 ) $ (1,671 )
Schedule of Interest Rate Swaption Agreements Outstanding	The following tables summarize our interest rate payer swaption agreements, U.S. Treasury securities and U.S. Treasury futures outstanding as of December 31, 2016 and 2015 (dollars in millions): Payer Swaptions Option Underlying Payer Swap Years to Expiration Cost Fair Value Average Months to Expiration Notional Amount Average Fixed Pay Rate Average Receive Rate (LIBOR) Average Term (Years) December 31, 2016 Total ≤ 1 year $ 52 $ 22 6 $ 1,200 3.06% 3M 8.3 December 31, 2015 Total ≤ 1 year $ 74 $ 17 4 $ 2,150 3.51% 3M 7.0 U.S. Treasury Securities December 31, 2016 December 31, 2015 Maturity Face Amount Net Long / (Short) Cost Basis Net Fair Value Face Amount Net Long / (Short) Cost Basis Net Fair Value 5 years $ (400 ) $ (404 ) $ (392 ) $ (250 ) $ (249 ) $ (249 ) 7 years (3,056 ) (3,041 ) (2,930 ) (354 ) (353 ) (352 ) 10 years (4,416 ) (4,236 ) (4,132 ) (1,085 ) (1,078 ) (1,070 ) Total U.S. Treasury securities, net $ (7,872 ) $ (7,681 ) $ (7,454 ) $ (1,689 ) $ (1,680 ) $ (1,671 )
US government securities	U.S. Treasury Securities December 31, 2016 December 31, 2015 Maturity Face Amount Net Long / (Short) Cost Basis Net Fair Value Face Amount Net Long / (Short) Cost Basis Net Fair Value 5 years $ (400 ) $ (404 ) $ (392 ) $ (250 ) $ (249 ) $ (249 ) 7 years (3,056 ) (3,041 ) (2,930 ) (354 ) (353 ) (352 ) 10 years (4,416 ) (4,236 ) (4,132 ) (1,085 ) (1,078 ) (1,070 ) Total U.S. Treasury securities, net $ (7,872 ) $ (7,681 ) $ (7,454 ) $ (1,689 ) $ (1,680 ) $ (1,671 )
US Government Futures Securities [Table Text Block]	U.S. Treasury Futures December 31, 2016 December 31, 2015 Maturity Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 5 years $ (730 ) $ (862 ) $ (859 ) $ 3 $ (730 ) $ (866 ) $ (864 ) $ 2 10 years (1,080 ) (1,347 ) (1,342 ) 5 (1,130 ) (1,424 ) (1,422 ) 2 Total U.S. Treasury futures $ (1,810 ) $ (2,209 ) $ (2,201 ) $ 8 $ (1,860 ) $ (2,290 ) $ (2,286 ) $ 4 _____________________ 1. U.S. Treasury futures notional amount represents the par value (or principal balance) of the underlying U.S. Treasury security. 2. U.S. Treasury futures cost basis represents the forward price to be paid/(received) for the underlying U.S. Treasury security. 3. U.S. Treasury futures market value represents the current market value of U.S. Treasury futures as of period-end. 4. Net carrying value represents the difference between the fair value and the cost basis of U.S. Treasury futures 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	The following tables summarize our TBA securities as of December 31, 2016 and 2015 (in millions): December 31, 2016 December 31, 2015 TBA Securities by Coupon Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 15-Year TBA securities: 2.5% $ 1,853 $ 1,870 $ 1,856 $ (14 ) $ (80 ) $ (81 ) $ (80 ) $ 1 3.0% 292 302 300 (2 ) 225 233 232 (1 ) 3.5% 15 16 16 — 136 143 142 (1 ) Total 15-Year TBA securities 2,160 2,188 2,172 (16 ) 281 295 294 (1 ) 30-Year TBA securities: 3.0% 3,027 3,114 3,007 (107 ) 3,914 3,911 3,916 5 3.5% 1,209 1,251 1,236 (15 ) 1,497 1,536 1,539 3 4.0% 4,530 4,769 4,760 (9 ) 1,575 1,658 1,665 7 4.5% (10 ) (10 ) (10 ) — 28 30 30 — Total 30-Year TBA securities, net 8,756 9,124 8,993 (131 ) 7,014 7,135 7,150 15 Total TBA securities, net $ 10,916 $ 11,312 $ 11,165 $ (147 ) $ 7,295 $ 7,430 $ 7,444 $ 14 December 31, 2016 December 31, 2015 TBA Securities by Issuer Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Notional Amount - Long (Short) 1 Cost Basis 2 Market Value 3 Net Carrying Value 4 Fannie Mae $ 9,881 $ 10,251 $ 10,118 $ (133 ) $ 6,033 $ 6,145 $ 6,159 $ 14 Freddie Mac 1,035 1,060 1,047 (13 ) 689 703 703 — Ginnie Mae — 1 — (1 ) 573 582 582 — TBA securities, net $ 10,916 $ 11,312 $ 11,165 $ (147 ) $ 7,295 $ 7,430 $ 7,444 $ 14 _____________________ 1. Notional amount represents the par value (or principal balance) of the underlying Agency security. 2. Cost basis represents the forward price to be paid/(received) for the underlying Agency security. 3. Market value represents the current market value of the TBA contract (or of the underlying Agency security) as of period-end. 4. Net carrying value represents the difference between the market value and the cost basis 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 tables below summarize changes in our derivative and other hedge portfolio and their effect on our consolidated statements of comprehensive income for fiscal years 2016 , 2015 and 2014 (in millions): Fiscal Year 2016 Derivative and Other Hedging Instruments Notional Amount December 31, 2015 Additions Settlement, Termination, Expiration or Exercise Notional Amount December 31, 2016 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 7,295 116,439 (112,818 ) $ 10,916 $ (59 ) Interest rate swaps $ 40,525 15,650 (19,000 ) $ 37,175 (397 ) Payer swaptions $ 2,150 500 (1,450 ) $ 1,200 (3 ) U.S. Treasury securities - short position $ (1,714 ) (9,884 ) 3,537 $ (8,061 ) 134 U.S. Treasury securities - long position $ 25 961 (797 ) $ 189 7 U.S. Treasury futures contracts - short position $ (1,860 ) (7,840 ) 7,890 $ (1,810 ) (5 ) $ (323 ) ________________________________ 1. Excludes a net loss of $3 million from debt of consolidated VIEs and other miscellaneous net gains of $16 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Fiscal Year 2015 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount December 31, 2015 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 14,412 119,922 (127,039 ) $ 7,295 $ 305 Interest rate swaps $ 43,700 4,950 (8,125 ) $ 40,525 (932 ) Payer swaptions $ 6,800 1,500 (6,150 ) $ 2,150 (35 ) Receiver swaptions $ (4,250 ) — 4,250 $ — 4 U.S. Treasury securities - short position $ (5,392 ) (12,503 ) 16,181 $ (1,714 ) (68 ) U.S. Treasury securities - long position $ 2,411 33,525 (35,911 ) $ 25 (38 ) U.S. Treasury futures contracts - short position $ (730 ) (4,480 ) 3,350 $ (1,860 ) (12 ) $ (776 ) ______________________ 1. Excludes a net gain of $16 million from debt of consolidated VIEs and other miscellaneous net losses of $4 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Fiscal Year 2014 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount December 31, 2014 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 2,119 213,627 (201,334 ) $ 14,412 $ 1,117 Interest rate swaps $ 43,250 20,550 (20,100 ) $ 43,700 (1,838 ) Payer swaptions $ 14,250 5,250 (12,700 ) $ 6,800 (193 ) Receiver swaptions $ — (5,500 ) 1,250 $ (4,250 ) 11 U.S. Treasury securities - short position $ (2,007 ) (36,489 ) 33,104 $ (5,392 ) (420 ) U.S. Treasury securities - long position $ 3,927 18,549 (20,065 ) $ 2,411 66 U.S. Treasury futures contracts - short position $ (1,730 ) (2,920 ) 3,920 $ (730 ) (76 ) TBA put option $ — (150 ) 150 $ — — $ (1,333 ) ______________________ 1. Excludes a net gain of $75 million from investments in REIT equity securities, a net loss of $10 million from debt of consolidate VIEs and other miscellaneous net losses of $7 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income.
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Schedule Of Interest Rate Swap Agreement By Remaining Maturity	The following table summarizes our interest rate swap agreements outstanding as of December 31, 2016 and 2015 (dollars in millions): December 31, 2016 December 31, 2015 Payer Interest Rate Swaps Notional 1 Average Rate 2 Average 3 Net Average Notional 1 Average Rate 2 Average 3 Net Average ≤ 3 years $ 19,775 1.16% 0.92% $ 39 1.5 $ 14,775 1.06% 0.40% $ (23 ) 1.6 > 3 to ≤ 5 years 7,450 1.62% 0.91% 44 4.0 9,950 2.03% 0.40% (203 ) 4.0 > 5 to ≤ 7 years 4,725 1.89% 0.91% 28 5.9 7,175 2.47% 0.44% (230 ) 6.1 > 7 to ≤ 10 years 3,325 1.90% 0.91% 114 9.2 7,450 2.57% 0.39% (342 ) 8.3 > 10 years 1,900 2.64% 0.91% (9 ) 13.8 1,175 3.20% 0.39% (91 ) 14.7 Total $ 37,175 1.48% 0.92% $ 216 3.9 $ 40,525 1.89% 0.40% $ (889 ) 4.6 ________________________

Pledged Assets (Tables)

Pledged Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Pledged Assets [Abstract]
Schedule of Securities and Cash Pledged as Collateral from Counterparties [Table Text Block]	As of December 31, 2016 and 2015 , we had assets pledged to us from counterparties as collateral under our reverse repurchase, repurchase and derivative agreements summarized in the tables below (in millions). December 31, 2016 December 31, 2015 Assets Pledged to AGNC Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total Agency MBS - fair value $ — $ — $ 14 $ 14 $ — $ — $ — $ — U.S. Treasury securities - fair value 7,636 — — 7,636 1,702 — — 1,702 Cash — 107 — 107 — — — — Total $ 7,636 $ 107 $ 14 $ 7,757 $ 1,702 $ — $ — $ 1,702
Schedule of Financial Instruments Owned and Pledged as Collateral	The following tables summarize our assets pledged as collateral under our funding, derivative and prime broker agreements by type, including securities pledged related to securities sold but not yet settled, as of December 31, 2016 and 2015 (in millions): December 31, 2016 Assets Pledged to Counterparties Repurchase Agreements and FHLB Advances 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements Total Agency RMBS - fair value $ 43,005 $ 818 $ 275 $ 865 $ 44,963 Non-Agency RMBS - fair value 90 — — — 90 U.S. Treasury securities - fair value 173 — — — 173 Accrued interest on pledged securities 122 3 1 2 128 Restricted cash and cash equivalents 60 — 14 — 74 Total $ 43,450 $ 821 $ 290 $ 867 $ 45,428 ______________________ 1. Includes $181 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements. December 31, 2015 Assets Pledged to Counterparties Repurchase Agreements and FHLB Advances 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements Total Agency RMBS - fair value $ 47,992 $ 1,029 $ 148 $ 485 $ 49,654 Non-Agency RMBS - fair value 113 — — — 113 U.S. Treasury securities - fair value 25 — — — 25 Accrued interest on pledged securities 135 3 — 2 140 Restricted cash and cash equivalents 23 — 1,226 32 1,281 Total $ 48,288 $ 1,032 $ 1,374 $ 519 $ 51,213 ______________________ 1. Includes $245 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements.
Schedules Of Securities Pledged As Collateral Under Repurchase Agreement	The following table summarizes our securities pledged as collateral under our repurchase agreements and FHLB advances by the remaining maturity of our borrowings, including securities pledged related to sold but not yet settled securities, as of December 31, 2016 and 2015 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 4 . December 31, 2016 December 31, 2015 Securities Pledged by Remaining Maturity of Repurchase Agreements and FHLB Advances 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 RMBS: 1 ≤ 30 days $ 19,681 $ 19,863 $ 56 $ 20,053 $ 20,075 $ 57 > 30 and ≤ 60 days 8,103 8,158 23 8,311 8,340 23 > 60 and ≤ 90 days 4,034 4,070 11 7,534 7,525 21 > 90 days 11,278 11,380 32 12,207 12,187 34 Total MBS 43,096 43,471 122 48,105 48,127 135 U.S. Treasury securities: 1 day — — — 25 25 — > 1 day ≤ 30 days 173 173 — — — — Total $ 43,269 $ 43,644 $ 122 $ 48,130 $ 48,152 $ 135 ______________________ 1. Includes $181 million and $245 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of December 31, 2016 and 2015 , respectively.
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, 2016 and 2015 (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, 2016 Interest rate swap and swaption agreements, at fair value 1 $ 342 $ — $ 342 $ (80 ) $ (49 ) $ 213 TBA 4 — 4 (4 ) — — Receivable under reverse repurchase agreements 7,716 — 7,716 (6,963 ) (753 ) — Total $ 8,062 $ — $ 8,062 $ (7,047 ) $ (802 ) $ 213 December 31, 2015 Interest rate swap and swaption agreements, at fair value 1 $ 48 $ — $ 48 $ (31 ) $ — $ 17 TBA 29 — 29 (15 ) — 14 Receivable under reverse repurchase agreements 1,713 — 1,713 (1,356 ) (357 ) — Total $ 1,790 $ — $ 1,790 $ (1,402 ) $ (357 ) $ 31
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, 2016 Interest rate swap agreements, at fair value 1 $ 105 $ — $ 105 $ (80 ) $ (25 ) $ — TBA 151 — 151 (4 ) (147 ) — Repurchase agreements and FHLB advances 40,895 — 40,895 (6,963 ) (33,932 ) — Total $ 41,151 $ — $ 41,151 $ (7,047 ) $ (34,104 ) $ — December 31, 2015 Interest rate swap agreements, at fair value 1 $ 920 $ — $ 920 $ (31 ) $ (889 ) $ — TBA 15 15 (15 ) — — Repurchase agreements and FHLB advances 45,507 — 45,507 (1,356 ) (44,151 ) — Total $ 46,442 $ — $ 46,442 $ (1,402 ) $ (45,040 ) $ — _______________________ 1. Reported under derivative assets/liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 5 for a reconciliation of derivative assets/liabilities, at fair value to their sub-components. 2. Includes cash and securities pledged/received as collateral, at fair value. Amounts presented are limited to collateral pledged sufficient to reduce the net amount to zero for individual counterparties, as applicable.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
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, 2016 and 2015 (in millions): December 31, 2016 December 31, 2015 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 45,393 $ — $ — $ 51,331 $ — Agency securities transferred to consolidated VIEs — 818 — — 1,029 — Non-Agency securities — 124 — — 113 — Credit risk transfer securities — 164 — — — — U.S. Treasury securities 182 — — 25 — — Interest rate swaps — 321 — — 31 — Swaptions — 22 — — 17 — TBA securities — 4 — — 29 — U.S. Treasury futures 8 — — 4 — — REIT equity securities — — — 33 — — Total $ 190 $ 46,846 $ — $ 62 $ 52,550 $ — Liabilities: Debt of consolidated VIEs $ — $ 460 $ — $ — $ 595 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 7,636 — — 1,696 — — Interest rate swaps — 105 — — 920 — TBA securities — 151 — — 15 — Total $ 7,636 $ 716 $ — $ 1,696 $ 1,530 $ —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Dividends Declared [Table Text Block]	Dividends Declared Dividends Declared Per Share 8.000 % Series A Cumulative Redeemable Preferred Stock Fiscal year 2016 $ 14 $ 2.000000 Fiscal year 2015 $ 14 $ 2.000000 Fiscal year 2014 $ 14 $ 2.000000 7.750% Series B Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2016 $ 14 $ 1.937500 Fiscal year 2015 $ 14 $ 1.937500 Fiscal year 2014 $ 6 $ 0.844965 Common Stock Fiscal year 2016 $ 763 $ 2.300000 Fiscal year 2015 $ 863 $ 2.480000 Fiscal year 2014 $ 921 $ 2.610000
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes changes to accumulated OCI for fiscal years 2016 , 2015 and 2014 (in millions): Accumulated Other Comprehensive Income (Loss) Net Unrealized Gain (Loss) on Available-for-Sale MBS Net Unrealized Gain (Loss) on Swaps Total Accumulated OCI Balance Balance as of December 31, 2013 $ (1,087 ) $ (296 ) $ (1,383 ) OCI before reclassifications 1,708 — 1,708 Amounts reclassified from accumulated OCI (51 ) 156 105 Balance as of December 31, 2014 570 (140 ) 430 OCI before reclassifications (620 ) — (620 ) Amounts reclassified from accumulated OCI 23 101 124 Balance as of December 31, 2015 (27 ) (39 ) (66 ) OCI before reclassifications (261 ) — (261 ) Amounts reclassified from accumulated OCI (109 ) 39 (70 ) Balance as of December 31, 2016 $ (397 ) $ — $ (397 ) The following table summarizes reclassifications out of accumulated OCI for fiscal years 2016 and 2015 (in millions): Fiscal Year Line Item in the Consolidated Statements of Comprehensive Income Where Net Income is Presented Amounts Reclassified from Accumulated OCI 2016 2015 2014 (Gain) loss amounts reclassified from accumulated OCI for available-for-sale MBS upon realization $ (109 ) $ 23 $ (51 ) Gain (loss) on sale of mortgage-backed securities, net Periodic interest costs of interest rate swaps previously designated as hedges under GAAP, net 39 101 156 Interest expense Total reclassifications $ (70 ) $ 124 $ 105

Equity Incentive Plan (Tables)

Equity Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2016
Share-based Compensation [Abstract]
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]	Director Plan Shares of Restricted Stock Restricted Stock Units Weighted Average Grant Date Fair Value 1 Weighted Average Vest Date Fair Value 2 Unvested balance as of December 31, 2013 27,000 — $ 30.37 $ — Granted — 16,770 $ 22.36 $ — Accrued RSU dividend equivalents — 1,469 $ — $ — Vested (13,000 ) — $ 30.01 $ 22.01 Unvested balance as of December 31, 2014 14,000 18,239 $ 25.11 $ — Granted — 28,880 $ 21.64 $ — Accrued RSU dividend equivalents — 3,319 $ — $ — Vested (9,000 ) (19,007 ) $ 23.17 $ 21.03 Unvested balance as of December 31, 2015 5,000 31,431 $ 21.44 $ — Granted — 33,015 $ 18.93 $ — Accrued RSU dividend equivalents — 3,527 $ — $ — Vested (5,000 ) (46,538 ) $ 20.00 $ 18.99 Unvested balance as of December 31, 2016 — 21,435 $ 17.49 $ —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Dividends Declared [Table Text Block]	Dividends Declared Dividends Declared Per Share 8.000 % Series A Cumulative Redeemable Preferred Stock Fiscal year 2016 $ 14 $ 2.000000 Fiscal year 2015 $ 14 $ 2.000000 Fiscal year 2014 $ 14 $ 2.000000 7.750% Series B Cumulative Redeemable Preferred Stock (Per Depositary Share) Fiscal year 2016 $ 14 $ 1.937500 Fiscal year 2015 $ 14 $ 1.937500 Fiscal year 2014 $ 6 $ 0.844965 Common Stock Fiscal year 2016 $ 763 $ 2.300000 Fiscal year 2015 $ 863 $ 2.480000 Fiscal year 2014 $ 921 $ 2.610000

Business Combination - Acquis32

Business Combination - Acquisition of AGNC Mortgage Management, LLC (Tables)	12 Months Ended
	Dec. 31, 2016
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The following table summarizes the fair values of assets acquired and liabilities assumed at the acquisition date (in millions). July 1, 2016 (Acquisition Date) Cash $ 7 MTGE management agreement 29 Other intangible asset 1 Total identifiable assets 37 Accounts payable and other liabilities (1 ) Identifiable net assets acquired 36 Goodwill 526 Net assets acquired $ 562

Business Combination - Acquis33

Business Combination - Acquisition of AGNC Mortgage Management, LLC Pro Forma Consolidated Revenue and Net Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2016
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustments [Table Text Block]	Pro Forma Consolidated Revenue and Net Income Fiscal Year 2016 2015 Revenue $ 1,337 $ 1,483 Net Income $ 661 $ 303

Quarterly Results (Tables)

Quarterly Results (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following is a presentation of the quarterly results of operations and comprehensive income for fiscal years 2016 and 2015 (in millions, except per share data). Quarter Ended March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 Interest income: Interest income $ 295 $ 318 $ 315 $ 393 Interest expense 99 101 96 98 Net interest income 196 217 219 295 Other gain (loss): Gain (loss) on sale of investment securities, net (2 ) 55 61 (5 ) Unrealized gain (loss) on investment securities measured at fair value through net income, net 11 — (6 ) (11 ) Gain (loss) on derivative instruments and other securities, net (944 ) (367 ) 248 753 Management fee income — — 4 4 Total other gain (loss), net (935 ) (312 ) 307 741 Expenses: Management fee expense 27 25 — — Compensation and benefits — — 9 10 Other operating expenses 6 15 6 7 Total expenses 33 40 15 17 Net income (loss) (772 ) (135 ) 511 1,019 Dividend on preferred stock 7 7 7 7 Net income (loss) available (attributable) to common shareholders $ (779 ) $ (142 ) $ 504 $ 1,012 Net income (loss) $ (772 ) $ (135 ) $ 511 $ 1,019 Other comprehensive income (loss): Unrealized gain (loss) on available-for-sale securities, net 765 370 (97 ) (1,408 ) Unrealized gain on derivative instruments, net 19 12 7 1 Other comprehensive income (loss) 784 382 (90 ) (1,407 ) Comprehensive income (loss) 12 247 421 (388 ) Dividend on preferred stock 7 7 7 7 Comprehensive income (loss) available (attributable) to common shareholders $ 5 $ 240 $ 414 $ (395 ) Weighted average number of common shares outstanding - basic and diluted 334.4 331.0 331.0 331.0 Net income (loss) per common share - basic and diluted $ (2.33 ) $ (0.43 ) $ 1.52 $ 3.06 Comprehensive income (loss) per common share - basic and diluted $ 0.01 $ 0.73 $ 1.25 $ (1.19 ) Dividends declared per common share $ 0.60 $ 0.60 $ 0.56 $ 0.54 Quarter Ended March 31, June 30, 2015 September 30, December 31, 2015 Interest income: Interest income $ 383 $ 414 $ 295 $ 374 Interest expense 86 81 77 86 Net interest income 297 333 218 288 Other gain (loss): Gain (loss) on sale of investment securities, net 36 (22 ) (39 ) 2 Unrealized gain (loss) on investment securities measured at fair value through net income, net 11 (7 ) 10 (9 ) Gain (loss) on derivative instruments and other securities, net (560 ) 244 (788 ) 340 Total other gain (loss), net (513 ) 215 (817 ) 333 Expenses: Management fees 30 29 29 28 General and administrative expenses 6 7 5 5 Total expenses 36 36 34 33 Net income (loss) (252 ) 512 (633 ) 588 Dividend on preferred stock 7 7 7 7 Net income (loss) available (attributable) to common shareholders $ (259 ) $ 505 $ (640 ) $ 581 Net income (loss) $ (252 ) $ 512 $ (633 ) $ 588 Other comprehensive income (loss): Unrealized gain (loss) on available-for-sale securities, net 391 (872 ) 467 (583 ) Unrealized gain on derivative instruments, net 29 26 24 22 Other comprehensive income (loss) 420 (846 ) 491 (561 ) Comprehensive income (loss) 168 (334 ) (142 ) 27 Dividend on preferred stock 7 7 7 7 Comprehensive income (loss) available (attributable) to common shareholders $ 161 $ (341 ) $ (149 ) $ 20 Weighted average number of common shares outstanding-basic and diluted 352.8 352.1 347.8 341.6 Net income (loss) per common share - basic and diluted $ (0.73 ) $ 1.43 $ (1.84 ) $ 1.70 Comprehensive income (loss) per common share - basic and diluted $ 0.46 $ (0.97 ) $ (0.43 ) $ 0.06 Dividends declared per common share $ 0.66 $ 0.62 $ 0.60 $ 0.60

Organization (Details)

Organization (Details)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Required distribution of taxable net income on a annual basis	90.00%
Intended annual distribution of taxable net income	100.00%

Summary of Significant Accoun36

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Jul. 01, 2016
Derivative [Line Items]
Excise Tax Rate	4.00%
Goodwill	$ 526	$ 526
Required Annual Distribution of Taxable Net Income	90.00%
Intangible Assets, Net (Excluding Goodwill)	$ 28

Summary of Significant Accoun37

Summary of Significant Accounting Policies Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2016	Jul. 01, 2016
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 526	$ 526
Intangible Assets, Net (Excluding Goodwill)	$ 28

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	$ 46,499	$ 52,473
Weighted average expected constant prepayment rate	8.00%	8.00%
Agency securities, total fair value	$ 800
Debt, at fair value	460	$ 595
Principal balance of agency securities collaterizing debt issued by securitization trust	(800)	(1,000)
Principal amount	452	587
Gain (loss) associated with consolidated debt	(3)	16	$ (10)
Fair value of CMO securities and interest-only and principal-only strips	1,100	1,300
Securitized CMO Securities	1,500	1,800
CMO and Interest Only, Principal Only Securities, Maximum Loss Exposure	182	238
Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unamortized premium balance	2,100	2,300
TBA securities Fifteen Year and Thirty Year Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Net long TBA position, at fair value	11,200	7,400
TBA, net carrying value	$ (147)	$ 14
Credit Risk Transfer Securities [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	4.60%
Underlying Collateral Coupon	4.00%
Credit Risk Transfer Securities [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	7.10%
Underlying Collateral Coupon	4.20%

Investment Securities (Summary

Investment Securities (Summary of Investment in Agency Security) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Amortized cost	$ 46,414	$ 52,147
Commercial Mortgage Backed Securities Unrealized Gain	0
Commercial Mortgage Backed Securities Unrealized Loss	0
Non-Agency Securities Unrealized Gain	0	0
Non-Agency Securities Unrealized Loss	(1)	(1)
Mortgage Backed Securities Amortized Cost	46,866	52,464
Mortgage Backed Securities Unrealized Gain	259	407
Mortgage Backed Securities Unrealized Loss	(626)	(398)
Gross unrealized gain	256	407
Gross unrealized loss	(625)	(397)
Fair value	46,017	52,120
Credit Risk Transfer Securities Unrealized Gain	3
Credit Risk Transfer Securities Unrealized Loss	0
Total agency MBS, amortized cost	46,580	52,350
Total agency MBS, at fair value	46,211	52,360
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	46,499	52,473
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Amortized cost	102	114
Fair value	101
Interest-only and principal-only strips, fair value		113
Commercial Mortgage Backed Securities [Member]
Amortized cost	23
Fair value	23
Credit Risk Transfer Securities [Member]
Interest-only and principal-only strips, amortized cost	161
Interest-only and principal-only strips, fair value	164
Fixed Income Securities [Member]
Gross unrealized gain	210	339
Gross unrealized loss	(619)	(393)
Fixed Income Securities [Member] | Agency Securities [Member]
Amortized cost	45,145	50,576
Fair value	44,736	50,522
Adjustable-Rate [Member]
Gross unrealized gain	8	11
Gross unrealized loss	0	0
Adjustable-Rate [Member] | Agency Securities [Member]
Amortized cost	371	484
Fair value	379	495
Collateralized Mortgage Obligations [Member]
Gross unrealized gain	7	18
Gross unrealized loss	(2)	1
Collateralized Mortgage Obligations [Member] | Agency Securities [Member]
Amortized cost	796	973
Fair value	801	990
Interest Only And Principal Only Strip [Member]
Gross unrealized gain	31	39
Gross unrealized loss	(4)	3
Interest Only And Principal Only Strip [Member] | Agency Securities [Member]
Interest-only and principal-only strips, amortized cost	268	317
Interest-only and principal-only strips, fair value	$ 295	$ 353

Investment Securities (Componen

Investment Securities (Components Of Investment Securities) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Agency securities transferred to consolidated VIEs		$ 818	$ 1,029
Amortized cost		46,414	52,147
Total agency MBS, at fair value		46,211	52,360
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure		$ 46,499	$ 52,473
Weighted average coupon		3.61%	3.63%
Weighted average yield		2.77%	2.78%	[1]
Unamortized Principal Balance Of Interest Only Strips		$ 900	$ 1,000
Future Prepayment Rate Assumption Of Investment Portfolio		8.00%	8.00%
Non-Agency Securities Unrealized Gain		$ 0	$ 0
Non-Agency Securities Unrealized Loss		(1)	(1)
Mortgage Backed Securities Amortized Cost		46,866	52,464
Mortgage Backed Securities Unrealized Gain		259	407
Mortgage Backed Securities Unrealized Loss		(626)	(398)
Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		44,397	49,955
Unamortized discount		(46)	(36)
Unamortized premium		2,063	2,228
Amortized cost		46,414	52,147
Gross unrealized gains		225	368
Gross unrealized losses		(622)	(395)
Total available-for-sale securities, at fair value		46,017	52,120
Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Securities Remeasured at Fair Value through earnings, Amortized Cost		452	317
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		34	39
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		(4)	(3)
Securities Remeasured at Fair Value Through Earnings, Debt Securities		482	353
Securities remeasured at fair value through earnings, Par Value		352	208
Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		(36)	(42)
Unamortized premium		136	151
Fannie Mae [Member]
Schedule of Investments [Line Items]
Total agency MBS, at fair value		$ 35,732	$ 41,214
Weighted average coupon		3.59%	3.62%
Weighted average yield	[1]	2.77%	2.79%
Fannie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 34,244	$ 39,205
Unamortized discount		(43)	(32)
Unamortized premium		1,518	1,707
Amortized cost		35,719	40,880
Gross unrealized gains		176	286
Gross unrealized losses		(442)	(283)
Total available-for-sale securities, at fair value		35,453	40,883
Fannie Mae [Member] | Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Securities Remeasured at Fair Value through earnings, Amortized Cost		254	298
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		28	35
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		(3)	(2)
Securities Remeasured at Fair Value Through Earnings, Debt Securities		279	331
Securities remeasured at fair value through earnings, Par Value		171	208
Fannie Mae [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		(35)	(42)
Unamortized premium		118	132
Freddie Mac [Member]
Schedule of Investments [Line Items]
Total agency MBS, at fair value		$ 10,434	$ 11,081
Weighted average coupon		3.67%	3.69%
Weighted average yield	[1]	2.72%	2.77%
Freddie Mac [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 10,008	$ 10,575
Unamortized discount		(3)	(4)
Unamortized premium		544	519
Amortized cost		10,549	11,090
Gross unrealized gains		48	80
Gross unrealized losses		(179)	(111)
Total available-for-sale securities, at fair value		10,418	11,059
Freddie Mac [Member] | Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Securities Remeasured at Fair Value through earnings, Amortized Cost		14	19
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		3	4
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		(1)	(1)
Securities Remeasured at Fair Value Through Earnings, Debt Securities		16	22
Securities remeasured at fair value through earnings, Par Value		0	0
Freddie Mac [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		0	0
Unamortized premium		14	19
Ginnie Mae [Member]
Schedule of Investments [Line Items]
Total agency MBS, at fair value		$ 45	$ 65
Weighted average coupon		2.75%	3.18%
Weighted average yield	[1]	2.00%	1.97%
Ginnie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 44	$ 62
Unamortized discount		0	0
Unamortized premium		0	1
Amortized cost		44	63
Gross unrealized gains		1	2
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		45	65
Ginnie Mae [Member] | Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Securities Remeasured at Fair Value through earnings, Amortized Cost		0	0
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		0	0
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		0	0
Securities Remeasured at Fair Value Through Earnings, Debt Securities		0	0
Securities remeasured at fair value through earnings, Par Value		0	0
Ginnie Mae [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		0	0
Unamortized premium		0	0
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Investments [Line Items]
Amortized cost		102	114
Total Securities		$ 101	$ 113
Weighted average coupon		3.42%	3.50%
Weighted average yield	[1]	3.27%	3.33%
Trading Securities, Other			$ 113
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 101	113
Unamortized discount		0	0
Unamortized premium		1	1
Amortized cost		102	114
Gross unrealized gains		0	0
Gross unrealized losses		(1)	(1)
Total available-for-sale securities, at fair value		101	113
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Securities Remeasured at Fair Value through earnings, Amortized Cost		0	0
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		0	0
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		0	0
Securities Remeasured at Fair Value Through Earnings, Debt Securities		0	0
Securities remeasured at fair value through earnings, Par Value		0	0
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		0	0
Unamortized premium		0	0
Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized cost		23
Total Securities		$ 23
Weighted average coupon		6.55%
Weighted average yield	[1]	7.54%
Commercial Mortgage Backed Securities [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 0
Unamortized discount		0
Unamortized premium		0
Amortized cost		0
Gross unrealized gains		0
Gross unrealized losses		0
Total available-for-sale securities, at fair value		0
Commercial Mortgage Backed Securities [Member] | Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Securities Remeasured at Fair Value through earnings, Amortized Cost		23
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		0
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		0
Securities Remeasured at Fair Value Through Earnings, Debt Securities		23	0
Securities remeasured at fair value through earnings, Par Value		24
Commercial Mortgage Backed Securities [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		(1)
Unamortized premium		$ 0
Credit Risk Transfer Securities [Member]
Schedule of Investments [Line Items]
Weighted average coupon		5.25%
Weighted average yield		6.28%
Trading Securities, Other		$ 164
Credit Risk Transfer Securities [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		0
Unamortized discount		0
Unamortized premium		0
Amortized cost		0
Gross unrealized gains		0
Gross unrealized losses		0
Total available-for-sale securities, at fair value		0
Credit Risk Transfer Securities [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		0
Unamortized premium		4
Securities Remeasured at Fair Value through earnings, Amortized Cost		161
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		3
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		0
Securities Remeasured at Fair Value Through Earnings, Debt Securities		164	$ 0
Securities remeasured at fair value through earnings, Par Value		157
Total Securities		$ 164
[1]	Incorporates a weighted average future constant prepayment rate assumption of 8% based on forward rates as of December 31, 2016

Investment Securities (Summar41

Investment Securities (Summary Of Agency Securities Estimated Weighted Average Life Classifications) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Agency securities classified as available for sale, Fair value	$ 46,017	$ 52,120
Agency securities classified as available for sale, Amortized cost	$ 46,414	$ 52,147
Weighted Average Coupon	3.52%	3.54%
Weighted Average Yield	2.73%	2.75%
Greater Than One Year and Less Than or Equal to Three Years [Member]
Fair Value	$ 414	$ 167
Amortized Cost	$ 410	$ 163
Weighted Average Coupon	3.99%	4.02%
Weighted Average Yield	2.52%	2.66%
Greater Than Three Years and Less Than or Equal to Five Years [Member]
Fair Value	$ 13,534	$ 17,497
Amortized Cost	$ 13,449	$ 17,343
Weighted Average Coupon	3.26%	3.27%
Weighted Average Yield	2.40%	2.40%
Greater Than Five Years [Member]
Fair Value	$ 30,226	$ 34,206
Amortized Cost	$ 30,713	$ 34,391
Weighted Average Coupon	3.65%	3.67%
Weighted Average Yield	2.86%	2.93%
Greater Than Ten Years [Member]
Fair Value	$ 1,843	$ 250
Amortized Cost	$ 1,842	$ 250
Weighted Average Coupon	3.02%	3.56%
Weighted Average Yield	3.07%	3.08%

Investment Securities (Summar42

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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Unrealized Gains and (Losses), Net	$ (1,408)	$ (97)	$ 370	$ 765	$ (583)	$ 467	$ (872)	$ 391	$ (370)	$ (597)	$ 1,657
Agency Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning OCI Balance				$ (27)				$ 570	(27)	570	(1,087)
Unrealized Gains and (Losses), Net									(261)	(620)	1,708
Reversal of Unrealized (Gains) and Losses, Net on Realization									(109)	23	(51)
Ending OCI Balance	$ (397)				$ (27)				$ (397)	$ (27)	$ 570

Investment Securities (Summar43

Investment Securities (Summary Of Continuous Unrealized Loss Positions Of Available-For-Sale Security) (Details) - Accumulated Other Comprehensive Income (Loss) [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Unrealized Loss Position For - Estimated Fair Value - Less than 12 Months	$ 28,397	$ 24,035
Unrealized Loss Position For - Unrealized Loss - Less than 12 Months	(554)	(200)
Unrealized Loss Position For - Estimated Fair Value - 12 Months or More	1,719	6,793
Unrealized Loss Position For - Unrealized Loss - 12 Months or More	(68)	(195)
Unrealized Loss Position For - Estimated Fair Value - Total	30,116	30,828
Unrealized Loss Position For - Unrealized Loss - Total	$ (622)	$ (395)

Investment Securities (Summar44

Investment Securities (Summary Of Net Gain From Sale Of Agency Securities) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Gain Loss on Other Debt									$ (3)	$ 16	$ (10)
Proceeds from agency MBS sold									10,393	48,354	56,068
Net gain (loss) on sale of RMBS	$ (5)	$ 61	$ 55	$ (2)	$ 2	$ (39)	$ (22)	$ 36	109	(23)	51
Available-for-sale Securities [Member]
Agency MBS sold, at cost									(17,907)	(27,578)	(30,123)
Proceeds from agency MBS sold									18,016	27,555	30,174
Net gain (loss) on sale of RMBS									109	(23)	51
Gross gain on sale of RMBS									123	98	172
Gross loss on sale of RMBS									$ (14)	$ (121)	$ (121)

Investment Securities Securitie

Investment Securities Securities by Credit Rating (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Securities Remeasured at Fair Value [Member] | Credit Risk Transfer Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	$ 164	$ 0
Available-for-sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Securities	46,017	52,120
Available-for-sale Securities [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Securities	101	113
Available-for-sale Securities [Member] | Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Securities	0
Available-for-sale Securities [Member] | Credit Risk Transfer Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Securities	0
Agency securities remeasured at fair value through earnings [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	482	353
Agency securities remeasured at fair value through earnings [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	0	0
Agency securities remeasured at fair value through earnings [Member] | Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	23	0
BBB Rating [Member] | Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	23	0
AAA Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	99	113
B Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	2	0
B Rating [Member] | Credit Risk Transfer Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	$ 164	$ 0

Repurchase Agreements And Oth46

Repurchase Agreements And Other Debt (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	$ 37,858	$ 41,754
Debt of consolidated variable interest entities, at fair value	$ 460	$ 595
Description of variable rate basis	LIBOR
Basis spread over LIBOR	36	34
Principal amount	$ 452	$ 587
Weighted average life of other debt	5 years 9 months 18 days	4 years 10 months 24 days
TBA securities Fifteen Year and Thirty Year Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Fair Value, Net	$ (147)	$ 14
TBA and Forward Settling Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Forward Settlement Value	11,312	7,430
Derivative, Fair Value, Net	(147)	14
US Treasury Securities [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	0	25
Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	$ 37,686	$ 41,729

Repurchase Agreements And Oth47

Repurchase Agreements And Other Debt (Repurchase Arrangements And Weighted Average Interest Rates Classified By Original Maturities) (Details) $ in Millions	Dec. 31, 2016USD ($)days	Dec. 31, 2015USD ($)days
Repurchase Agreements | $	$ 37,858	$ 41,754
Weighted Average Days to Maturity | days	186	173
30 Days or Less [Member]
Repurchase Agreements | $	$ 17,481	$ 17,579
Weighted Average Interest Rate	0.90%	0.54%
Weighted Average Days to Maturity | days	11	14
1 to 3 Months
Repurchase Agreements | $	$ 10,011	$ 14,283
Weighted Average Interest Rate	0.93%	0.64%
Weighted Average Days to Maturity | days	55	58
3 to 6 Months
Repurchase Agreements | $	$ 2,030	$ 3,154
Weighted Average Interest Rate	1.02%	0.61%
Weighted Average Days to Maturity | days	136	121
6 to 9 Months
Repurchase Agreements | $	$ 1,270	$ 589
Weighted Average Interest Rate	0.98%	0.65%
Weighted Average Days to Maturity | days	214	199
9 to 12 Months
Repurchase Agreements | $	$ 1,566	$ 1,201
Weighted Average Interest Rate	1.08%	0.65%
Weighted Average Days to Maturity | days	299	307
12 to 24 Months
Repurchase Agreements | $	$ 1,203	$ 1,473
Weighted Average Interest Rate	1.28%	0.73%
Weighted Average Days to Maturity | days	538	600
24 to 36 Months
Repurchase Agreements | $	$ 1,300	$ 650
Weighted Average Interest Rate	1.36%	0.81%
Weighted Average Days to Maturity | days	865	901
36 to 48 months
Repurchase Agreements | $	$ 2,200	$ 1,300
Weighted Average Interest Rate	1.32%	0.86%
Weighted Average Days to Maturity | days	1,168	1,231
48 to 60 Months
Repurchase Agreements | $	$ 625	$ 1,500
Weighted Average Interest Rate	1.38%	0.76%
Weighted Average Days to Maturity | days	1,506	1,477
Maturity Overnight [Member]
Weighted Average Interest Rate	0.00%	0.00%
Weighted Average Days to Maturity | days	0	1
2 Days to 1 Month [Member]
Weighted Average Interest Rate	(0.30%)	0.00%
Weighted Average Days to Maturity | days	17	0
Repurchase Agreements [Member]
Weighted Average Interest Rate	0.98%	0.61%
Agency Securities [Member]
Repurchase Agreements | $	$ 37,686	$ 41,729
Weighted Average Days to Maturity | days	187	173
Agency Securities [Member] | Repurchase Agreements [Member]
Weighted Average Interest Rate	0.98%	0.61%
US Treasury Securities [Member] | Maturity Overnight [Member]
Repurchase Agreements | $	$ 0	$ 25
US Treasury Securities [Member] | 2 Days to 1 Month [Member]
Repurchase Agreements | $	$ 172	$ 0

Repurchase Agreements And Oth48

Repurchase Agreements And Other Debt Federal Home Loan Bank Advances and Weighted Average Interest Rates (Details) $ in Millions	Dec. 31, 2016USD ($)days	Dec. 31, 2015USD ($)days
Short-term Debt [Line Items]
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.73%	0.53%
FHLB Weighted Average Days to Maturity | days	28	141
Advances from Federal Home Loan Banks | $	$ 3,037	$ 3,753
Maturity Less than 30 Days [Member]
Short-term Debt [Line Items]
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.67%	0.47%
FHLB Weighted Average Days to Maturity | days	7	14
Advances from Federal Home Loan Banks | $	$ 1,353	$ 1,952
thirty one to ninety [Member]
Short-term Debt [Line Items]
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.77%	0.60%
FHLB Weighted Average Days to Maturity | days	44	84
Advances from Federal Home Loan Banks | $	$ 1,684	$ 681
13 Months [Member]
Short-term Debt [Line Items]
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.00%	0.58%
FHLB Weighted Average Days to Maturity | days	0	397
Advances from Federal Home Loan Banks | $	$ 0	$ 1,120

Derivative and Other Hedging 49

Derivative and Other Hedging Instruments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Forward Contracts [Member] | Interest Rate Swap [Member]
Average Maturity (Years)									10 years 8 months 12 days	5 years 6 months
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net									$ (3)	$ (35)	$ (193)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period									500	1,500	5,250
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period									(1,450)	(6,150)	(12,700)
TBA and Forward Settling Agency Securities [Member]
Notional Amount	$ 10,916				$ 7,295				10,916	7,295	14,412	$ 2,119
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net									(59)	305	1,117
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period									116,439	119,922	213,627
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period										(127,039)	(201,334)
US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net									(5)	(12)	(76)
Gain Loss on Other Debt									(3)	16	(10)
Unrealized gain on derivative instruments, net	1	$ 7	$ 12	$ 19	22	$ 24	$ 26	$ 29	39	101	156
Net periodic interest costs on swaps									294	494	486
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion									255	393	330
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net									(323)	(776)	(1,333)
Gain (loss) on REIT Equity Securities										(4)	75
Discontinuation of Election to Account for Interest Rate Swaps as Designated Cash Flow Hedges [Member]
Net Unrealized Gain (Loss) on Swaps	0				39				0	39	140	296
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Notional Amount	1,200								1,200
Short [Member] | US Treasury Securities [Member]
Notional Amount	8,061				1,714				8,061	1,714	5,392	2,007
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net									134	(68)	(420)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period									9,884	12,503	36,489
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period									(3,537)	(16,181)	(33,104)
Long [Member] | US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net									7	(38)	66
Trading Securities Added During the Period									961	33,525	18,549
Notional Amount Of Trading Securities Settlement Expiration During The Period									(797)	(35,911)	(20,065)
Trading Securities					$ 25					$ 25	2,411	$ 3,927
Long [Member]
Trading Securities	$ 189								189
Other Derivatives [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net									$ 16		$ (7)

Derivative and Other Hedging 50

Derivative and Other Hedging Instruments (Fair Value Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Derivative asset, fair value	$ 355	$ 81
Derivative liability, fair value	(256)	(935)
Derivative assets, at fair value	355	81
Derivative Liability	(256)	(935)
U.S. Treasury securities	182	25
U.S. Treasury Securities - short	(7,636)	(1,696)
Total - (short)/long, net	(7,454)	(1,671)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(323)	(776)	$ (1,333)
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	10,916	7,295	14,412	$ 2,119
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	116,439	119,922	213,627
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		(127,039)	(201,334)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(59)	305	1,117
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	37,175	40,525
Derivative liability, fair value	(105)	(920)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	15,650	4,950	20,550
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(19,000)	(8,125)	(20,100)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(397)	(932)	(1,838)
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	321	31
Interest Rate Swaption [Member]
Derivative [Line Items]
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	500	1,500	5,250
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(1,450)	(6,150)	(12,700)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(3)	(35)	(193)
Interest Rate Swaption [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	22	17
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative liability, fair value	(151)	(15)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(112,818)
Receiver Swaption [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		4	11
US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(5)	(12)	(76)
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member] | Future [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative [Line Items]
Derivative assets, at fair value		4
Derivative Liability	8
TBA and Forward Settling Agency Securities [Member] | Fair Value, Measurements, 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	4	29
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	37,175
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	1,200
Not Designated as Hedging Instrument [Member] | Receiver Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount		0
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period		0	(5,500)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		4,250	1,250
Short [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	8,061	1,714	5,392	2,007
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	9,884	12,503	36,489
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(3,537)	(16,181)	(33,104)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	134	(68)	(420)
Long [Member]
Derivative [Line Items]
Trading Securities	189
Long [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	7	(38)	66
Trading Securities		25	2,411	$ 3,927
Trading Securities Added During the Period	961	33,525	18,549
Notional Amount Of Trading Securities Settlement Expiration During The Period	$ (797)	$ (35,911)	$ (20,065)

Derivative and Other Hedging 51

Derivative and Other Hedging Instruments (Summary Of Outstanding Interest Rate Swaps) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Gain Loss on Other Debt	$ (3)	$ 16	$ (10)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (323)	$ (776)	(1,333)
Forward Contracts [Member] | Interest Rate Swap [Member]
Average Maturity (Years)	10 years 8 months 12 days	5 years 6 months
Derivative, Notional Amount	$ 600	$ 4,500
Weighted Average Forward Start Date	1 year 2 months 12 days	8 months 12 days
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (397)	$ (932)	(1,838)
Notional Amount	$ 37,175	$ 40,525
Average Fixed Pay Rate	1.48%	1.89%
Average Receive Rate	0.92%	0.40%
Net Estimated Fair Value	$ 216	$ (889)
Average Maturity (Years)	3 years 10 months 24 days	4 years 7 months 6 days
Greater Than One Year and Less Than or Equal to Three Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 19,775	$ 14,775
Average Fixed Pay Rate	1.16%	1.06%
Average Receive Rate	0.92%	0.40%
Net Estimated Fair Value	$ 39	$ (23)
Average Maturity (Years)	1 year 6 months	1 year 7 months 6 days
Greater Than Three Years and Less Than or Equal to Five Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 7,450	$ 9,950
Average Fixed Pay Rate	1.62%	2.03%
Average Receive Rate	0.91%	0.40%
Net Estimated Fair Value	$ 44	$ (203)
Average Maturity (Years)	4 years	4 years
Greater Than Five Years and Less than or Equal to Seven Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 4,725	$ 7,175
Average Fixed Pay Rate	1.89%	2.47%
Average Receive Rate	0.91%	0.44%
Net Estimated Fair Value	$ 28	$ (230)
Average Maturity (Years)	5 years 10 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	$ 3,325	$ 7,450
Average Fixed Pay Rate	1.90%	2.57%
Average Receive Rate	0.91%	0.39%
Net Estimated Fair Value	$ 114	$ (342)
Average Maturity (Years)	9 years 2 months 12 days	8 years 3 months 18 days
Greater Than Ten Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 1,900	$ 1,175
Average Fixed Pay Rate	2.64%	3.20%
Average Receive Rate	0.91%	0.39%
Net Estimated Fair Value	$ (9)	$ (91)
Average Maturity (Years)	13 years 9 months 18 days	14 years 8 months 12 days
Other Derivatives [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 16		$ (7)

Derivative and Other Hedging 52

Derivative and Other Hedging Instruments (Remaining Interest Rate Swap Term) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)month	Dec. 31, 2015USD ($)month	Dec. 31, 2014USD ($)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (323)	$ (776)	$ (1,333)
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(3)	(35)	(193)
Receiver Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		4	11
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(397)	(932)	(1,838)
Derivative Liability, Notional Amount	$ 37,175	$ 40,525
Average Fixed Pay Rate	1.48%	1.89%
Average Maturity (Years)	3 years 10 months 24 days	4 years 7 months 6 days
Less Than or Equal to One Year [Member] | Interest Rate Swaption [Member]
Cost	$ 52	$ 74
Fair Value	$ 22	$ 17
Average Months to Expiration | month	6	4
Derivative Liability, Notional Amount	$ 1,200	$ 2,150
Average Fixed Pay Rate	3.06%	3.51%
Average Maturity (Years)	8 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	$ 19,775	$ 14,775
Average Fixed Pay Rate	1.16%	1.06%
Average Maturity (Years)	1 year 6 months	1 year 7 months 6 days
Other Derivatives [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 16		$ (7)
Interest Rate Swaps Excluding Forward Starting [Member] | Interest Rate Swap [Member]
Average Fixed Pay Rate	1.46%	1.75%

Derivative and Other Hedging 53

Derivative and Other Hedging Instruments (US Treasury Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
U.S. Treasury securities, net	$ (7,454)	$ (1,671)
7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(3,056)	(354)
At Par Value [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(7,872)	(1,689)
US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	8	4
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(10,916)	(7,295)
Derivative, Forward Settlement Value	(11,312)	(7,430)
Derivative Asset, Fair Value, Gross Asset	(11,165)	(7,444)
Derivative, Fair Value, Net	(147)	14
5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(400)	(250)
10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(4,416)	(1,085)
10 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	5	2
5 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	3	2
Short [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,810)	(1,860)
Derivative, Forward Settlement Value	(2,209)	(2,290)
Derivative Asset, Fair Value, Gross Asset	(2,201)	(2,286)
Short [Member] | 10 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,080)	(1,130)
Derivative, Forward Settlement Value	(1,347)	(1,424)
Derivative Asset, Fair Value, Gross Asset	(1,342)	(1,422)
Short [Member] | 5 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(730)	(730)
Derivative, Forward Settlement Value	(862)	(866)
Derivative Asset, Fair Value, Gross Asset	(859)	(864)
Fair Value Hedging [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(7,454)	(1,671)
Fair Value Hedging [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(2,930)	(352)
Fair Value Hedging [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(392)	(249)
Fair Value Hedging [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(4,132)	(1,070)
At Cost Basis [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(7,681)	(1,680)
At Cost Basis [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(3,041)	(353)
At Cost Basis [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(404)	(249)
At Cost Basis [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	$ (4,236)	$ (1,078)

Derivative and Other Hedging 54

Derivative and Other Hedging Instruments (TBA Securities by Coupon and Issuer) (Details) - TBA and Forward Settling Agency Securities [Member] - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative, Notional Amount	$ (10,916)	$ (7,295)
Cost Basis	(11,312)	(7,430)
Net long TBA position, at fair value	(11,165)	(7,444)
TBA, net carrying value	(147)	14
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Derivative [Line Items]
Derivative, Notional Amount	0	(573)
Cost Basis	(1)	(582)
Net long TBA position, at fair value	0	(582)
TBA, net carrying value	(1)	0
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,035)	(689)
Cost Basis	(1,060)	(703)
Net long TBA position, at fair value	(1,047)	(703)
TBA, net carrying value	(13)	0
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Derivative [Line Items]
Derivative, Notional Amount	(9,881)	(6,033)
Cost Basis	(10,251)	(6,145)
Net long TBA position, at fair value	(10,118)	(6,159)
TBA, net carrying value	(133)	14
30 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	(8,756)	(7,014)
Cost Basis	(9,124)	(7,135)
Net long TBA position, at fair value	(8,993)	(7,150)
TBA, net carrying value	(131)	15
30 Year Maturity [Member] | 3.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(3,027)	(3,914)
Cost Basis	(3,114)	(3,911)
Net long TBA position, at fair value	(3,007)	(3,916)
TBA, net carrying value	(107)	5
30 Year Maturity [Member] | 3.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,209)	(1,497)
Cost Basis	(1,251)	(1,536)
Net long TBA position, at fair value	(1,236)	(1,539)
TBA, net carrying value	(15)	3
30 Year Maturity [Member] | 4.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(4,530)	(1,575)
Cost Basis	(4,769)	(1,658)
Net long TBA position, at fair value	(4,760)	(1,665)
TBA, net carrying value	(9)	7
30 Year Maturity [Member] | 4.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount		(28)
Cost Basis		(30)
Net long TBA position, at fair value		(30)
TBA, net carrying value	0	0
30 Year Maturity [Member] | Short [Member] | 4.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(10)
Cost Basis	(10)
Net long TBA position, at fair value	(10)
15 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	(2,160)	(281)
Cost Basis	(2,188)	(295)
Net long TBA position, at fair value	(2,172)	(294)
TBA, net carrying value	(16)	(1)
15 Year Maturity [Member] | 2.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,853)
Cost Basis	(1,870)
Net long TBA position, at fair value	(1,856)
TBA, net carrying value	(14)	1
15 Year Maturity [Member] | 3.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(292)	(225)
Cost Basis	(302)	(233)
Net long TBA position, at fair value	(300)	(232)
TBA, net carrying value	(2)	(1)
15 Year Maturity [Member] | 3.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(15)	(136)
Cost Basis	(16)	(143)
Net long TBA position, at fair value	(16)	(142)
TBA, net carrying value	$ 0	(1)
15 Year Maturity [Member] | Short [Member] | 2.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount		(80)
Cost Basis		(81)
Net long TBA position, at fair value		$ (80)

Derivative and Other Hedging 55

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, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	$ (323)	$ (776)	$ (1,333)
Gain (loss) on REIT Equity Securities		(4)	75
Gain Loss on Other Debt	(3)	16	(10)
Put Option [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount		0
Additions			150
Settlement, Expirations or Exercise			(150)
Notional Amount			0
Receiver Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives		4	11
Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Additions	(500)	(1,500)	(5,250)
Settlement, Expirations or Exercise	1,450	6,150	12,700
Amount Gain/(Loss) Recognized in Income on Derivatives	(3)	(35)	(193)
TBA and Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(7,295)	(14,412)	(2,119)
Additions	(116,439)	(119,922)	(213,627)
Settlement, Expirations or Exercise		127,039	201,334
Notional Amount	(10,916)	(7,295)	(14,412)
Amount Gain/(Loss) Recognized in Income on Derivatives	(59)	305	1,117
Derivative, Notional Amount	(10,916)	(7,295)
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Settlement, Expirations or Exercise	112,818
Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(40,525)
Additions	(15,650)	(4,950)	(20,550)
Settlement, Expirations or Exercise	19,000	8,125	20,100
Notional Amount	(37,175)	(40,525)
Amount Gain/(Loss) Recognized in Income on Derivatives	(397)	(932)	(1,838)
US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	(5)	(12)	(76)
Other derivative instruments [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	16		(7)
Not Designated as Hedging Instrument [Member] | Receiver Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	0
Additions		0	5,500
Settlement, Expirations or Exercise		(4,250)	(1,250)
Notional Amount		0
Derivative, Notional Amount			(4,250)	$ 0
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(1,200)
Derivative, Notional Amount		(2,150)	(6,800)	(14,250)
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(37,175)
Derivative, Notional Amount		(40,525)	(43,700)	(43,250)
Short [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(1,714)	(5,392)	(2,007)
Additions	(9,884)	(12,503)	(36,489)
Settlement, Expirations or Exercise	3,537	16,181	33,104
Notional Amount	(8,061)	(1,714)	(5,392)
Amount Gain/(Loss) Recognized in Income on Derivatives	134	(68)	(420)
Derivative, Notional Amount	(1,810)	(1,860)
Long [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Trading Securities	189
Long [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	7	(38)	66
Trading Securities		25	2,411	$ 3,927
Trading Securities Added During the Period	961	33,525	18,549
Notional Amount Of Trading Securities Settlement Expiration During The Period	(797)	(35,911)	(20,065)
Future [Member] | Short [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(1,860)	(730)	(1,730)
Additions	(7,840)	(4,480)	(2,920)
Settlement, Expirations or Exercise	7,890	3,350	3,920
Notional Amount	$ (1,810)	$ (1,860)	$ (730)

Pledged Assets (Narrative) (Det

Pledged Assets (Narrative) (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Pledged Assets [Abstract]
Federal Home Loan Bank Stock	$ 126,000,000	$ 150,000,000
Risk Of Repurchase Agreement To Stockholders Equity	6.00%	5.00%
Risk of interest swap and swaption agreements to stockholders' equity	$ 0.01

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, 2016USD ($)daysmonth	Dec. 31, 2015USD ($)days
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Securities Sold under Agreements to Repurchase	$ 37,858	$ 41,754
Risk Of Repurchase Agreement To Stockholders Equity	6.00%	5.00%
Weighted Average Days to Maturity | days	186	173
J.P. Morgan Securities, LLC [Member]
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Securities Sold under Agreements to Repurchase	$ 4,875
Risk Of Repurchase Agreement To Stockholders Equity	5.50%
Counterparty Exposure, Net	$ 405
Repurchase Agreements Weighted Average Months To Maturity | month	34.1

Pledged Assets (Assets Pledged

Pledged Assets (Assets Pledged as Collateral) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Offsetting Assets and Liabilities [Line Items]
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repurchase Agreements	$ 181	$ 245
Federal Home Loan Bank Stock	126	150
Available-for-sale Securities Pledged as Collateral	43,943	48,380
Accrued interest on pledged securities	128	140
Restricted cash and cash equivalents	74	1,281
Total Fair Value of Securities Pledged and Accrued Interest	45,428
Total Fair Value Of Agency Securities Pledged And Accrued Interest		51,213
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	43,005	47,992
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	275	148
Accrued interest on pledged securities		0
Restricted cash and cash equivalents	14	1,226
Total Fair Value of Securities Pledged and Accrued Interest	290
Total Fair Value Of Agency Securities Pledged And Accrued Interest		1,374
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Accrued interest on pledged securities	122	135
Total Fair Value of Securities Pledged and Accrued Interest	43,450
Total Fair Value Of Agency Securities Pledged And Accrued Interest		48,288
Variable Interest Entity, Primary Beneficiary [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	818	1,029
Accrued interest on pledged securities	3	3
Total Fair Value of Securities Pledged and Accrued Interest	821
Total Fair Value Of Agency Securities Pledged And Accrued Interest		1,032
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	865	485
Accrued interest on pledged securities	2	2
Total Fair Value of Securities Pledged and Accrued Interest	867
Total Fair Value Of Agency Securities Pledged And Accrued Interest		519
Includes Sold But Not Yet Settled Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	44,963	49,654
AAA Non-Agency Mortgage-Backed Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	90	113
AAA Non-Agency Mortgage-Backed Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	90	113
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	173	25
US Treasury Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	173	25
US Treasury Securities [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	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	60	23
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash and cash equivalents	0	32
Excluding Cash Received [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash and cash equivalents	$ 74	$ 1,281

Pledged Assets (Securities Pled

Pledged Assets (Securities Pledged as Collateral) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Offsetting Assets and Liabilities [Line Items]
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repo	$ 181	$ 245
Security Owned and Pledged as Collateral, Fair Value	43,269	48,130
Agency Securities Pledged As Collateral Amortized Cost	43,644	48,152
Agency Securities Pledged As Collateral Accrued Interest	122	135
Maturity Less than 30 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	19,681	20,053
Agency Securities Pledged As Collateral Amortized Cost	19,863	20,075
Agency Securities Pledged As Collateral Accrued Interest	56	57
Maturity 31 To 59 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	8,103	8,311
Agency Securities Pledged As Collateral Amortized Cost	8,158	8,340
Agency Securities Pledged As Collateral Accrued Interest	23	23
Maturity 60 To 90 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	4,034	7,534
Agency Securities Pledged As Collateral Amortized Cost	4,070	7,525
Agency Securities Pledged As Collateral Accrued Interest	11	21
Maturity over 90 days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	11,278	12,207
Agency Securities Pledged As Collateral Amortized Cost	11,380	12,187
Agency Securities Pledged As Collateral Accrued Interest	32	34
Maturity Overnight [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	0	25
Agency Securities Pledged As Collateral Amortized Cost	0	25
Agency Securities Pledged As Collateral Accrued Interest	0	0
2 Days to 1 Month [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	173	0
Agency Securities Pledged As Collateral Amortized Cost	173	0
Agency Securities Pledged As Collateral Accrued Interest	0	0
Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	43,096	48,105
Agency Securities Pledged As Collateral Amortized Cost	43,471	48,127
Agency Securities Pledged As Collateral Accrued Interest	$ 122	$ 135

Pledged Assets (Assets Pledge60

Pledged Assets (Assets Pledged from Counterparties) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Offsetting Assets and Liabilities [Line Items]
Federal Home Loan Bank Stock	$ 126	$ 150
Available-for-sale Securities Pledged as Collateral	43,943	48,380
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	7,636	1,696
Restricted Cash and Cash Equivalents	74	1,281
Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	14	0
Restricted Cash and Cash Equivalents	107	0
Restricted Cash and Securities Pledged	7,757	1,702
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	14	0
Securities Sold under Agreements to Repurchase [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	14	0
Derivative [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	0
Restricted Cash and Securities Pledged	107	0
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	173	25
US Treasury Securities [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	7,636	1,702
Reverse Repurchase Agreements [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	7,636	1,702
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	275	148
Restricted Cash and Cash Equivalents	14	1,226
Derivative [Member] | US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	0
Derivative [Member] | US Treasury Securities [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	0
Derivative [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	$ 107	$ 0

Pledged Assets (Offsetting Asse

Pledged Assets (Offsetting Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Offsetting Assets and Liabilities [Line Items]
Collateral Received	$ (802)
Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	8,062	$ 1,790
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	8,062	1,790
Financial Instruments	(7,047)	(1,402)
Collateral Received		(357)
Net Amount	213	31
Assets [Member] | ERROR in label resolution.
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	342	48
Net Amounts of Assets Presented in the Consolidated Balance Sheets	342	48
Financial Instruments	(80)	(31)
Collateral Received	(49)	0
Net Amount	213	17
Assets [Member] | TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	4	29
Net Amounts of Assets Presented in the Consolidated Balance Sheets	4	29
Financial Instruments	(4)	(15)
Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	41,151	46,442
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	41,151	46,442
Financial Instruments	(7,047)	(1,402)
Collateral Received	(34,104)	(45,040)
Net Amount	0
Liability [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Net Amount	0
Liability [Member] | ERROR in label resolution.
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	105	920
Net Amounts of Assets Presented in the Consolidated Balance Sheets	105	920
Financial Instruments	(80)	(31)
Collateral Received	(25)	(889)
Net Amount	0	0
Liability [Member] | TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	151	15
Net Amounts of Assets Presented in the Consolidated Balance Sheets	151	15
Financial Instruments	(4)	(15)
Collateral Received	(147)	0
Net Amount	0	0
Reverse Repurchase Agreements [Member] | Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	7,716	1,713
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	7,716	1,713
Financial Instruments	(6,963)	(1,356)
Collateral Received	(753)	(357)
Repurchase Agreements [Member] | Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	40,895	45,507
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	40,895	45,507
Financial Instruments	(6,963)	(1,356)
Collateral Received	$ (33,932)	$ (44,151)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Future [Member] | Fair Value, Measurements, 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		$ 4
Derivative Liability	$ (8)
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	22	17
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	321	31
Interest Rate Swap [Member] | Derivative liabilities, at fair value [Member] | Fair Value, Measurements, 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	105	920
Purchases Of TBAs And Forward Settling Agency Securities [Member] | Fair Value, Measurements, 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	$ 4	29
Transfers between hierarchy levels	0
Agency securities	$ 45,393	51,331
Agency securities transferred to consolidated VIEs	818	1,029
Non-Agency Securities, at Fair Value	124	113
Financial Instruments, Owned, Other, at Fair Value	164	0
U.S. Treasury securities	182	25
TBA securities	355	81
Derivative Liability	256	935
Debt of consolidated variable interest entities, at fair value	460	595
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	7,636	1,696
Interest rate swaps	355	81
REIT equity securities, at fair value	0	33
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	190	62
Total liabilities	7,636	1,696
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	46,846	52,550
Total liabilities	716	1,530
Fair Value, Measurements, 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	$ 151	$ 15

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	May 31, 2014	Jun. 30, 2012	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2012	May 05, 2014	Apr. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Authorized			10,000,000	10,000,000
Preferred Stock Authorized, but not Issued			3,100,000
Issuance of preferred stock			$ 0	$ 0	$ 169
Preferred Stock, Shares Issued			6,900,000	6,900,000
Preferred Stock, Value, Issued			$ 336	$ 336
Preferred Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance			6,900,000
Sale of Stock, Price Per Share								$ 24.2125
Series A Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Dividend Rate, Percentage						8.00%
Issuance of preferred stock		$ 167
Preferred Stock, Liquidation Preference Per Share								$ 25
Preferred Class B [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance			8,050
Preferred Stock, Dividend Rate, Percentage					7.75%
Preferred Stock, Shares Issued							7,000,000
Share Price							$ 24.2125
Preferred Stock, Value, Issued							$ 169
Series B Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Liquidation Preference Per Share							$ 25
Preferred stock, percent interest per share	0.10%

Stockholders' Equity (Common St

Stockholders' Equity (Common Stock Repurchase Program) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 31, 2016	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchase Program, Authorized Amount	$ 2,000			$ 1,000
Repurchase of common stock shares	(6.5)	(15.3)	(3.4)
Average repurchase price (in dollars per share)	$ 17.89	$ 18.58	$ 22.10
Repurchase of common stock, value	$ 116	$ 285	$ 74
Payments for Repurchase of Common Stock	116	$ 285	$ 74
Remaining amount authorized for repurchase	$ 1,000				$ 600
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of common stock shares	(6.5)	(15.3)	(3.4)
Repurchase of common stock, value	$ 0	$ 1

Stockholders' Equity (Accumulat

Stockholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Accumulated OCI Balance	$ (397)				$ (66)				$ (397)	$ (66)	$ 430	$ (1,383)
OCI before reclassifications	(1,408)	$ (97)	$ 370	$ 765	(583)	$ 467	$ (872)	$ 391	(370)	(597)	1,657
Amounts reclassified from accumulated OCI	1	$ 7	$ 12	19	22	$ 24	$ 26	29	39	101	156
Total Accumulated OCI Balance									(70)	124	105
Agency Securities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning OCI Balance				$ (27)				$ 570	(27)	570	(1,087)
OCI before reclassifications									(261)	(620)	1,708
Amounts reclassified from accumulated OCI									(109)	23	(51)
Ending OCI Balance	(397)				(27)				(397)	(27)	570
Discontinuation of Election to Account for Interest Rate Swaps as Designated Cash Flow Hedges [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Unrealized Gain (Loss) on Swaps	$ 0				$ (39)				0	(39)	(140)	$ (296)
Interest Rate Swap [Member] | Agency Securities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
OCI before reclassifications									$ (261)	$ (620)	$ 1,708

Stockholders' Equity (Follow-On

Stockholders' Equity (Follow-On Equity Offerings) (Details) - shares shares in Millions	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares, Issued	331	337.5

Stockholders' Equity (At-the-Ma

Stockholders' Equity (At-the-Market Offering Program) (Details) - shares shares in Millions	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares, Issued	331	337.5

Stockholders' Equity (Long-term

Stockholders' Equity (Long-term Incentive Plan) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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	5,000	14,000	27,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 17.49	$ 21.44	$ 25.11	$ 30.37
Accrued RSU Dividend Equivalents	3,527	3,319	1,469
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	5,000	9,000	13,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 20	$ 23.17	$ 30.01
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Vest Date Fair Value	$ 18.99	$ 21.03	$ 22.01
Stock based compensation	$ 1,000,000	$ 0	$ 0
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	1,918,235
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock or Unit Expense	$ 625,000	$ 625,000	$ 375,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	21,435	31,431	18,239
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 18.93	$ 21.64	$ 22.36
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	33,015	28,880	16,770
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	46,538	19,007

Stockholders' Equity Schedule o

Stockholders' Equity Schedule of Dividends Declared (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 14	$ 14	$ 14
Dividends, Common Stock	$ 763	$ 863	$ 921
Common Stock, Dividends, Per Share, Cash Paid	$ 2.3	$ 2.48	$ 2.61
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 2	$ 2	$ 2
Preferred Class B [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends, Preferred Stock	$ 14	$ 14	$ 6
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 1.9375	$ 1.9375	$ 0.844965

Equity Incentive Plan (Details)

Equity Incentive Plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation [Abstract]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 1,918,235
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	0	5,000	14,000	27,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 17.49	$ 21.44	$ 25.11	$ 30.37
Accrued RSU Dividend Equivalents	3,527	3,319	1,469
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	5,000	9,000	13,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 20	$ 23.17	$ 30.01
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Vest Date Fair Value	$ 18.99	$ 21.03	$ 22.01

Equity Incentive Plan Narrative

Equity Incentive Plan Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 9 months 11 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	0	5,000	14,000	27,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 17.49	$ 21.44	$ 25.11	$ 30.37
Accrued RSU Dividend Equivalents	3,527	3,319	1,469
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(5,000)	(9,000)	(13,000)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 20	$ 23.17	$ 30.01
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Vest Date Fair Value	$ 18.99	$ 21.03	$ 22.01
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
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	101,407
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	9,900,000
Allocated Share-based Compensation Expense	$ 28,000
Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 731,000	$ 704,000	$ 540,000
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	21,435	31,431	18,239
Restricted Stock or Unit Expense	$ 625,000	$ 625,000	$ 375,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	33,015	28,880	16,770
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 18.93	$ 21.64	$ 22.36
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(46,538)	(19,007)
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	$ 1,814,182

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investments, Owned, Federal Income Tax Note [Line Items]
Required Annual Distribution of Taxable Net Income	90.00%
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 2	$ 2	$ 2
Dividends, Preferred Stock	$ 14	$ 14	$ 14
Common Stock, Dividends, Per Share, Cash Paid	$ 2.3	$ 2.48	$ 2.61
Dividends, Common Stock	$ 763	$ 863	$ 921
Preferred Class B [Member]
Investments, Owned, Federal Income Tax Note [Line Items]
Preferred Stock, Dividend Rate, Per-Dollar-Amount	$ 1.9375	$ 1.9375	$ 0.844965
Dividends, Preferred Stock	$ 14	$ 14	$ 6

Management Agreement and Rela73

Management Agreement and Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transactions [Abstract]
Management fees	$ 0	$ 0	$ 25	$ 27	$ 28	$ 29	$ 29	$ 30	$ 52	$ 116	$ 119
Labor and Related Expense	10	9	0	0					19	0	0
Related Party Transaction, Expenses from Transactions with Related Party									3	8	8
Management Fees Revenue	$ 4	$ 4	$ 0	$ 0					$ 8	$ 0	$ 0

Business Combination - Acquis74

Business Combination - Acquisition of AGNC Mortgage Management, LLC (Details) - USD ($) $ in Millions	Jul. 01, 2016	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Business Acquisition, Date of Acquisition Agreement	Jul. 1, 2016
Business Combination, Acquisition Related Costs						$ 9
Payments to Acquire Businesses, Gross	$ 562
Management Fees Revenue		$ 4	$ 4	$ 0	$ 0	8	$ 0	$ 0
Goodwill	526	$ 526				526
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	562
Income (Loss) from Subsidiaries, Net of Tax						$ (11)
Cash Acquired from Acquisition	7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	29
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	1
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	37
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(1)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	$ 36

Business Combination - Acquis75

Business Combination - Acquisition of AGNC Mortgage Management, LLC Pro Forma Consolidated Revenue and Net Income (loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Business Acquisition, Pro Forma Revenue	$ 1,337	$ 1,483
Business Acquisition, Pro Forma Net Income (Loss)	$ 661	$ 303

Quarterly Results (Details)

Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income	$ 393	$ 315	$ 318	$ 295	$ 374	$ 295	$ 414	$ 383	$ 1,321	$ 1,466	$ 1,472
Interest expense	98	96	101	99	86	77	81	86	394	330	372
Net interest income	295	219	217	196	288	218	333	297	927	1,136	1,100
Noninterest Income [Abstract]
Gain (loss) on sale of agency securities, net	(5)	61	55	(2)	2	(39)	(22)	36	109	(23)	51
Unrealized gain (loss) on investment securities measured at fair value through net income, net	(11)	(6)	0	11	(9)	10	(7)	11	(6)	5	32
(Loss) gain on derivative instruments and other securities, net	753	248	(367)	(944)	340	(788)	244	(560)	(310)	(764)	(1,275)
Management Fees Revenue	4	4	0	0					8	0	0
Total other (loss) income, net	741	307	(312)	(935)	333	(817)	215	(513)	(199)	(782)	(1,192)
Management fees	0	0	25	27	28	29	29	30	52	116	119
Labor and Related Expense	10	9	0	0					19	0	0
General and administrative expenses	7	6	15	6	5	5	7	6	34	23	22
Total expenses	17	15	40	33	33	34	36	36	105	139	141
Net income (loss)	1,019	511	(135)	(772)	588	(633)	512	(252)	623	215	(233)
Dividend on preferred stock	7	7	7	7	7	7	7	7	28	28	23
Net income (loss) available (attributable) to common shareholders	1,012	504	(142)	(779)	581	(640)	505	(259)	595	187	(256)
Unrealized Gains and (Losses), Net	(1,408)	(97)	370	765	(583)	467	(872)	391	(370)	(597)	1,657
Unrealized gain on derivative instruments, net	1	7	12	19	22	24	26	29	39	101	156
Other comprehensive (loss) income	(1,407)	(90)	382	784	(561)	491	(846)	420	(331)	(496)	1,813
Comprehensive (loss) income	(388)	421	247	12	27	(142)	(334)	168	292	(281)	1,580
Comprehensive (loss) income (attributable) available to common shareholders	$ (395)	$ 414	$ 240	$ 5	$ 20	$ (149)	$ (341)	$ 161	$ 264	$ (309)	$ 1,557
Weighted average number of common shares outstanding-basic and diluted	331,000,000	331,000,000	331,000,000	334,400,000	341,600,000	347,800,000	352,100,000	352,800,000	331,900,000	348,600,000	353,300,000
Earnings Per Share, Basic and Diluted	$ 3.06	$ 1.52	$ (0.43)	$ (2.33)	$ 1.70	$ (1.84)	$ 1.43	$ (0.73)	$ 1.79	$ 0.54	$ (0.72)
Comprehensive income per share - basic and diluted	(1.19)	1.25	0.73	0.01	0.06	(0.43)	(0.97)	0.46
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Common Stock, Dividends, Per Share, Declared	$ 0.54	$ 0.56	$ 0.60	$ 0.60	$ 0.60	$ 0.60	$ 0.62	$ 0.66

Subsequent Event (Details)

Subsequent Event (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions

Feb. 14, 2017

Jul. 01, 2016

Dec. 31, 2016

Sep. 30, 2016

Jun. 30, 2016

Mar. 31, 2016

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2016

Feb. 01, 2017

Subsequent Event [Line Items]

Payments to Acquire Businesses, Gross

$ 562

Business Combination, Acquisition Related Costs

$ 9

Dividends declared per common share

$ 0.54

$ 0.56

$ 0.60

$ 0.60

$ 0.60

$ 0.60

$ 0.62

$ 0.66

Subsequent Event [Member]

Subsequent Event [Line Items]

Dividends declared per common share

$ 0.18

At the Market Offering Program [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Common Stock, Capital Shares Reserved for Future Issuance

750