AGNC Investment (AGNC) 10-Q 8 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 30, 2017
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
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

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Assets:
Agency securities, at fair value (including pledged securities of $41,587 and $43,943, respectively)	$ 43,856	$ 45,393
Agency securities transferred to consolidated variable interest entities, at fair value (pledged securities)	777	818
Non-Agency securities, at fair value (including pledged securities of $0 and $90, respectively)	31	124
Credit risk transfer securities, at fair value	383	164
U.S. Treasury securities, at fair value (including pledged securities of $0 and $173, respectively)	0	182
Cash and cash equivalents	1,073	1,208
Restricted cash and cash equivalents	219	74
Derivative assets, at fair value	205	355
Receivable for securities sold (including pledged securities of $537 and $21, respectively)	688	21
Receivable under reverse repurchase agreements	8,908	7,716
Goodwill and other intangible assets, net	554	554
Other assets	144	271
Total assets	56,838	56,880
Liabilities:
Repurchase Agreements	39,375	37,858
Federal Home Loan Bank advances	0	3,037
Debt of consolidated variable interest entities, at fair value	434	460
Payable for securities purchased	693	0
Derivative liabilities, at fair value	69	256
Dividends payable	66	66
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	8,792	7,636
Accounts payable and other liabilities	117	211
Total liabilities	49,546	49,524
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 shares issued and outstanding	3	3
Additional paid-in capital	9,932	9,932
Retained deficit	(2,628)	(2,518)
Accumulated other comprehensive loss	(351)	(397)
Total stockholders' equity	7,292	7,356
Total liabilities and stockholders' equity	$ 56,838	$ 56,880

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Millions, $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Available-for-sale Securities Pledged as Collateral	$ 41,587	$ 43,943
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	331
Common Stock, Shares, Outstanding	331	331
Non-Agency Securities Pledged as Collateral	$ 0	$ 90
Trading Securities Pledged as Collateral	0	173
Assets Pledged included in Receivable for Securities Sold	$ 537	$ 21

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Interest income:
Interest income	$ 296	$ 295
Interest expense	98	99
Net interest income	198	196
Other income, net:
Loss on sale of investment securities, net	(84)	(2)
Unrealized gain on investment securities measured at fair value through net income, net	16	11
Loss on derivative instruments and other securities, net	(40)	(944)
Management fee income	3	0
Total other loss, net:	(105)	(935)
Expenses:
Management fee expense	0	27
Compensation and benefits	10	0
Other operating expenses	7	6
Total operating expenses	17	33
Net income (loss)	76	(772)
Dividend on preferred stock	7	7
Net income (loss) available (attributable) to common stockholders	69	(779)
Other comprehensive income (loss):
Unrealized gain on available-for-sale securities, net	(46)	(765)
Unrealized gain on derivative instruments, net	0	19
Other comprehensive income	46	784
Comprehensive income	122	12
Comprehensive income available to common stockholders	$ 115	$ 5
Weighted average number of common shares outstanding - basic	331	334.4
Weighted average number of common shares outstanding - diluted	331.1	334.4
Net income (loss) per common share - basic and diluted	$ 0.21	$ (2.33)
Dividends declared per common share	$ 0.54	$ 0.60

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, 2015	$ 7,971	$ 336	$ 3	$ 10,048	$ (2,350)	$ (66)
Balance, Preferred Stock, shares at Dec. 31, 2015		6.9
Balance, Common Stock, shares at Dec. 31, 2015			337.5
Net income (loss)	(772)				(772)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	765					765
Amounts reclassified from accumulated OCI	19					19
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	$ (7)				(7)
Common dividends declared	(200)				(200)
Balance, value at Mar. 31, 2016	7,660	$ 336	$ 3	9,932	(3,329)	718
Balance, Preferred Stock, shares at Mar. 31, 2016		6.9
Balance, Common Stock, shares at Mar. 31, 2016			331
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
Net income (loss)	$ 76				76
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	46					46
Amounts reclassified from accumulated OCI	0
Payments for Repurchase of Common Stock	0
Preferred dividends declared	(7)				(7)
Common dividends declared	(179)				(179)
Balance, value at Mar. 31, 2017	$ 7,292	$ 336	$ 3	$ 9,932	$ (2,628)	$ (351)
Balance, Preferred Stock, shares at Mar. 31, 2017	6.9	6.9
Balance, Common Stock, shares at Mar. 31, 2017	331		331

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities:
Net income (loss)	$ 76	$ (772)
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of premiums and discounts on mortgage-backed securities, net	89	150
Amortization of accumulated other comprehensive loss on interest rate swaps de-designated as qualifying hedges	0	19
Amortization of intangible assets	1	0
Loss on sale of investment securities, net	84	2
Unrealized loss on investment securities measured at fair value through net income, net	(16)	(11)
Loss on derivative instruments and other securities, net	40	944
Decrease in other assets	125	18
Increase (decrease) in accounts payable and other accrued liabilities	(9)	12
Net cash provided by operating activities	390	362
Investing activities:
Purchases of Agency mortgage-backed securities	(4,573)	(7,370)
Purchases of credit risk transfer and non-Agency securities	317	0
Proceeds from sale of Agency mortgage-backed securities	4,424	3,513
Proceeds from sale of credit risk transfer and non-Agency securities	193	0
Principal collections on Agency mortgage-backed securities	1,636	1,601
Principal collections on credit risk transfer and non-Agency securities	4	3
Purchases of U.S. Treasury securities	(1,748)	(739)
Proceeds from sale of U.S. Treasury securities	2,999	2,164
Net payments on reverse repurchase agreements	(1,192)	(1,450)
Net payments on derivative instruments	(208)	(586)
Other investing cash flows, net	(50)	31
Net cash provided by investing activities	1,168	(2,833)
Financing activities:
Proceeds from repurchase arrangements	77,905	62,155
Payments on repurchase agreements	(76,347)	(58,614)
Proceeds from Federal Home Loan Bank advances	0	2,098
Payments on Federal Home Loan Bank advances	(3,037)	(2,814)
Payments on debt of consolidated variable interest entities	(28)	(31)
Payments for common stock repurchases	0	(116)
Cash dividends paid	(186)	(208)
Net cash used in financing activities	(1,693)	2,470
Net change in cash and cash equivalents	(135)	(1)
Cash and cash equivalents at beginning of period	1,208	1,110
Cash and cash equivalents at end of period	$ 1,073	$ 1,109

Unaudited Interim Consolidated

Unaudited Interim Consolidated Financial Statements	3 Months Ended
	Mar. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Unaudited Interim Consolidated Financial Statements	Unaudited Interim Consolidated Financial Statements The unaudited interim consolidated financial statements of AGNC Investment Corp. (referred throughout this report as the "Company", "we", "us" and "our") are prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Article 10 of Regulation S-X. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. Our unaudited interim consolidated financial statements include the accounts of all of our wholly-owned subsidiaries and variable interest entities for which we are the primary beneficiary. Significant intercompany accounts and transactions have been eliminated. In the opinion of management, all adjustments, consisting solely of normal recurring accruals, necessary for the fair presentation of financial statements for the interim period have been included. The current period’s results of operations are not necessarily indicative of results that ultimately may be achieved for the year.

Organization

Organization	3 Months Ended
	Mar. 31, 2017
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 and commercial mortgage-backed securities ("non-Agency RMBS" and "CMBS," respectively), where repayment of principal and interest is not guaranteed by a U.S. Government-sponsored enterprise or U.S. Government agency (see Note 3 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 (our "Manager"). On July 1, 2016, we completed the acquisition of all of the outstanding membership interests of AGNC Mortgage Management, LLC ("AMM"), 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, the external manager of MTGE Investment Corp. ("MTGE") (NASDAQ: MTGE). Following the closing of the acquisition of AMM, we became internally managed and are no longer affiliated with ACAS.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies 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. Mortgage-related securities may also include investments in the common stock of other publicly traded mortgage REITs, including MTGE, which invest in Agency and non-Agency securities and/or other real estate related assets. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities , requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for such securities pursuant to ASC Topic 825, Financial Instruments . All of our securities are reported at fair value as they have either been designated as available-for-sale or trading or we have elected the fair value option of accounting. 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. 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 elected the fair value option to account for CRT, CMBS and Agency interest and principal-only securities and, effective January 1, 2017, for all Agency and non-Agency securities acquired on or after January 1, 2017. In our view, this election simplifies the accounting for such securities and more appropriately reflects the results of our operations for a particular reporting period, as the fair value changes for these assets are 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. Refer to Note 8 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. 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. 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. 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. Our derivative agreements require that we post or receive collateral on such agreements to such risk. We also attempt to minimize our risk of loss 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 was 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 the Chicago Mercantile Exchange ("CME"), a registered commodities exchange. 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. Our centrally cleared swaps require that we post an “initial margin” to our counterparties for an amount determined by the CME, which is generally intended to be set at a level sufficient to protect the CME from the maximum estimated single-day price movement in that market participant’s contracts. We also exchange cash “variation margin” with our counterparties on our centrally cleared swaps based upon daily changes in the fair value as measured by the CME. Beginning in the first quarter of 2017, as a result of a CME amendment to its rule book governing its central clearing activities, the daily exchange of variation margin associated with a CME centrally cleared derivative instrument is legally characterized as the daily settlement of the derivative instrument itself, as opposed to a pledge of collateral. Accordingly, beginning in 2017, we account for the daily receipt or payment of variation margin associated with our centrally cleared interest rate swaps as a direct reduction to the carrying value of the interest rate swap derivative asset or liability, respectively; and the carrying amount of centrally cleared interest rate swaps reflected in our consolidated balance sheets is equal to the unsettled fair value of such instruments. 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. 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 March 31, 2017, we did not accrue a loss contingency related to these matters. 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 2016-13, 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	3 Months Ended
	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities	3 years and ≤ 5 years 11,717 11,628 3.30% 2.42% 13,534 13,449 3.26% 2.40% > 5 years and ≤10 years 26,130 26,579 3.67% 2.85% 30,226 30,713 3.65% 2.86% > 10 years 526 528 3.08% 3.06% 1,843 1,842 3.02% 3.07% Total $ 39,120 $ 39,471 3.55% 2.72% $ 46,017 $ 46,414 3.52% 2.73% 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 March 31, 2017 and December 31, 2016 (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 March 31, 2017 $ 24,113 $ (490 ) $ 1,646 $ (67 ) $ 25,759 $ (557 ) December 31, 2016 $ 28,397 $ (554 ) $ 1,719 $ (68 ) $ 30,116 $ (622 ) We did not recognize any OTTI charges on our investment securities for the three months ended March 31, 2017 and 2016 . 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 investment securities for the three months ended March 31, 2017 and 2016 by investment classification of accounting (see Note 3 ) (in millions). Three Months Ended March 31, 2017 2016 Investment Securities Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale Securities 2 Fair Value Option Securities Total Investment securities sold, at cost $ (5,149 ) $ (26 ) $ (5,175 ) $ (3,515 ) $ — $ (3,515 ) Proceeds from investment securities sold 1 5,065 26 5,091 3,513 — 3,513 Net gain (loss) on sale of investment securities $ (84 ) $ — $ (84 ) $ (2 ) $ — $ (2 ) Gross gain on sale of investment securities $ 4 $ — $ 4 $ 5 $ — $ 5 Gross loss on sale of investment securities (88 ) — (88 ) (7 ) — (7 ) Net gain (loss) on sale of investment securities $ (84 ) $ — $ (84 ) $ (2 ) $ — $ (2 ) ________________________ 1. Proceeds include cash received during the period, plus receivable for investment securities sold during the period as of period end. 2. See Note 10 for a summary of changes in accumulated OCI. Securitizations and Variable Interest Entities As of March 31, 2017 and December 31, 2016 , 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 as of March 31, 2017 and December 31, 2016 and debt with a total fair value of $434 million and $460 million , respectively, in our accompanying consolidated balance sheets. As of March 31, 2017 and December 31, 2016 , the Agency securities had an aggregate unpaid principal balance of $0.7 billion and $0.8 billion , respectively, and the debt had an aggregate unpaid principal balance of $425 million and $452 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 the three months ended March 31, 2017 and 2016, we recorded a loss of $1 million and $5 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 March 31, 2017 and December 31, 2016 , the fair value of our CMO securities and interest and principal-only securities was $1.0 billion and $1.1 billion , respectively, excluding the consolidated CMO trusts discussed above, or $1.4 billion and $1.5 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 $167 million and $182 million as of March 31, 2017 and December 31, 2016 , respectively." id="sjs-B4">Investment Securities As of March 31, 2017 and December 31, 2016 , our investment portfolio consisted of $45.0 billion and $46.5 billion of investment securities, at fair value, respectively, summarized in the tables below, and $14.4 billion and $11.2 billion of net TBA securities, at fair value, respectively. Our TBA position is reported at its net carrying value of $70 million and $(147) million as of March 31, 2017 and December 31, 2016 , 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 6 for further details of our net TBA position as of March 31, 2017 and December 31, 2016 ). As of March 31, 2017 and December 31, 2016 , our investment securities had a net unamortized premium balance of $2.1 billion , including interest and principal-only securities. The following tables summarize our investment securities as of March 31, 2017 and December 31, 2016 (dollars in millions): March 31, 2017 December 31, 2016 Investment Securities Amortized Cost Fair Value Amortized Fair Value Agency RMBS: Fixed rate $ 43,585 $ 43,232 $ 45,145 $ 44,736 Adjustable rate 354 362 371 379 CMO 755 761 796 801 Interest-only and principal-only strips 254 278 268 295 Total Agency RMBS 44,948 44,633 46,580 46,211 Non-Agency RMBS 8 8 102 101 CMBS 23 23 23 23 CRT securities 375 383 161 164 Total investment securities $ 45,354 $ 45,047 $ 46,866 $ 46,499 March 31, 2017 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 28,651 $ 8,986 $ 41 $ 8 $ — $ — $ 37,686 Unamortized discount (27 ) (3 ) — — — — (30 ) Unamortized premium 1,325 489 1 — — — 1,815 Amortized cost 29,949 9,472 42 8 — — 39,471 Gross unrealized gains 156 49 1 — — — 206 Gross unrealized losses (393 ) (164 ) — — — — (557 ) Total available-for-sale securities, at fair value 29,712 9,357 43 8 — — 39,120 Securities remeasured at fair value through earnings: Par value 1 5,198 26 — — 24 364 5,612 Unamortized discount (40 ) — — — (1 ) — (41 ) Unamortized premium 286 14 — — — 11 311 Amortized cost 5,444 40 — — 23 375 5,882 Gross unrealized gains 40 3 — — — 8 51 Gross unrealized losses (5 ) (1 ) — — — — (6 ) Total securities remeasured at fair value through earnings 5,479 42 — — 23 383 5,927 Total securities, at fair value $ 35,191 $ 9,399 $ 43 $ 8 $ 23 $ 383 $ 45,047 Weighted average coupon as of March 31, 2017 3.65 % 3.68 % 2.76 % 2.50 % 6.55 % 5.17 % 3.67 % Weighted average yield as of March 31, 2017 2 2.83 % 2.71 % 2.00 % 2.97 % 7.54 % 5.85 % 2.83 % ________________________ 1. Par value amount excludes the underlying unamortized principal balance ("UPB") of interest-only securities of $0.9 billion as of March 31, 2017 . 2. Incorporates a weighted average future constant prepayment rate assumption of 8% based on forward rates as of March 31, 2017 . 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 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 . As of March 31, 2017 and December 31, 2016 , our investments in non-Agency securities had the following credit ratings: March 31, 2017 December 31, 2016 Non-Agency Security Credit Ratings 1 CRT RMBS CMBS CRT RMBS CMBS AAA $ — $ 8 $ — $ — $ 99 $ — BBB — — 23 — — 23 BB 31 — — — — — B 350 — — 164 2 — Not Rated 2 — — — — — Total $ 383 $ 8 $ 23 $ 164 $ 101 $ 23 ________________________ 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 underlying Agency RMBS issued by Fannie Mae or Freddie Mac, which were subject to their underwriting standards. As of March 31, 2017 , our CRT securities had floating rate coupons ranging from 4.3% to 7.3% , referenced to loans originated between 2012 and 2016 with weighted average coupons ranging from 3.6% to 4.2% . As of December 31, 2016 , our CRT securities had floating rate coupons ranging from 4.6% to 7.1% , referenced to loans originated between 2015 and 2016 with weighted average coupons ranging from 4.0% to 4.2% . 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 March 31, 2017 and December 31, 2016 , 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 March 31, 2017 and December 31, 2016 according to their estimated weighted average life classification (dollars in millions): March 31, 2017 December 31, 2016 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 $ 747 $ 736 3.90% 2.55% $ 414 $ 410 3.99% 2.52% > 3 years and ≤ 5 years 11,717 11,628 3.30% 2.42% 13,534 13,449 3.26% 2.40% > 5 years and ≤10 years 26,130 26,579 3.67% 2.85% 30,226 30,713 3.65% 2.86% > 10 years 526 528 3.08% 3.06% 1,843 1,842 3.02% 3.07% Total $ 39,120 $ 39,471 3.55% 2.72% $ 46,017 $ 46,414 3.52% 2.73% 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 March 31, 2017 and December 31, 2016 (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 March 31, 2017 $ 24,113 $ (490 ) $ 1,646 $ (67 ) $ 25,759 $ (557 ) December 31, 2016 $ 28,397 $ (554 ) $ 1,719 $ (68 ) $ 30,116 $ (622 ) We did not recognize any OTTI charges on our investment securities for the three months ended March 31, 2017 and 2016 . 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 investment securities for the three months ended March 31, 2017 and 2016 by investment classification of accounting (see Note 3 ) (in millions). Three Months Ended March 31, 2017 2016 Investment Securities Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale Securities 2 Fair Value Option Securities Total Investment securities sold, at cost $ (5,149 ) $ (26 ) $ (5,175 ) $ (3,515 ) $ — $ (3,515 ) Proceeds from investment securities sold 1 5,065 26 5,091 3,513 — 3,513 Net gain (loss) on sale of investment securities $ (84 ) $ — $ (84 ) $ (2 ) $ — $ (2 ) Gross gain on sale of investment securities $ 4 $ — $ 4 $ 5 $ — $ 5 Gross loss on sale of investment securities (88 ) — (88 ) (7 ) — (7 ) Net gain (loss) on sale of investment securities $ (84 ) $ — $ (84 ) $ (2 ) $ — $ (2 ) ________________________ 1. Proceeds include cash received during the period, plus receivable for investment securities sold during the period as of period end. 2. See Note 10 for a summary of changes in accumulated OCI. Securitizations and Variable Interest Entities As of March 31, 2017 and December 31, 2016 , 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 as of March 31, 2017 and December 31, 2016 and debt with a total fair value of $434 million and $460 million , respectively, in our accompanying consolidated balance sheets. As of March 31, 2017 and December 31, 2016 , the Agency securities had an aggregate unpaid principal balance of $0.7 billion and $0.8 billion , respectively, and the debt had an aggregate unpaid principal balance of $425 million and $452 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 the three months ended March 31, 2017 and 2016, we recorded a loss of $1 million and $5 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 March 31, 2017 and December 31, 2016 , the fair value of our CMO securities and interest and principal-only securities was $1.0 billion and $1.1 billion , respectively, excluding the consolidated CMO trusts discussed above, or $1.4 billion and $1.5 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 $167 million and $182 million as of March 31, 2017 and December 31, 2016 , respectively.

Repurchase Agreements And Other

Repurchase Agreements And Other Debt	3 Months Ended
	Mar. 31, 2017
Disclosure of Repurchase Agreements [Abstract]
Repurchase Agreements And Other Debt	1 to ≤ 3 months 8,728 1.02 % 55 10,011 0.93 % 55 > 3 to ≤ 6 months 1,831 0.97 % 121 2,030 1.02 % 136 > 6 to ≤ 9 months 3,668 1.10 % 224 1,270 0.98 % 214 > 9 to ≤ 12 months 1,361 1.11 % 284 1,566 1.08 % 299 > 12 to ≤ 24 months 1,588 1.43 % 524 1,203 1.28 % 538 > 24 to ≤ 36 months 2,300 1.50 % 961 1,300 1.36 % 865 > 36 to ≤ 48 months 1,325 1.49 % 1,302 2,200 1.32 % 1,168 > 48 to < 60 months — — % — 625 1.38 % 1,506 Total Agency repo 39,375 1.05 % 176 37,686 0.98 % 187 U.S. Treasury repo: > 1 day to ≤ 1 month — — % — 172 (0.30 )% 17 Total $ 39,375 1.05 % 176 $ 37,858 0.98 % 186 Federal Home Loan Bank Advances As of December 31, 2016 , we had $3.0 billion of outstanding secured Federal Home Loan Bank ("FHLB") advances, with a weighted average borrowing rate of 0.73% . Our FHLB advances matured in February 2017, coinciding with the termination of our wholly-owned captive insurance subsidiary's FHLB membership in February 2017 pursuant to the Federal Housing Finance Agency's ("FHFA") final rule on FHLB membership released in January 2016. As a result, we had no outstanding secured FHLB advances as of March 31, 2017 . Debt of Consolidated Variable Interest Entities As of March 31, 2017 and December 31, 2016 , debt of consolidated VIEs, at fair value, was $434 million and $460 million , respectively, and had a weighted average interest rate of LIBOR plus 37 and 36 basis points, respectively, and a principal balance of $425 million and $452 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 March 31, 2017 and December 31, 2016 was 5.8 years." id="sjs-B4">Repurchase Agreements and Other Secured Borrowings We pledge certain of our securities as collateral under our borrowing agreements with financial institutions. 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 March 31, 2017 , we had met all margin call requirements. For additional information regarding our pledged assets, please refer to Note 7 . Repurchase Agreements As of March 31, 2017 and December 31, 2016 , we had $39.4 billion and $37.9 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 March 31, 2017 and December 31, 2016 (dollars in millions): March 31, 2017 December 31, 2016 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 $ 18,574 0.94 % 13 $ 17,481 0.90 % 11 > 1 to ≤ 3 months 8,728 1.02 % 55 10,011 0.93 % 55 > 3 to ≤ 6 months 1,831 0.97 % 121 2,030 1.02 % 136 > 6 to ≤ 9 months 3,668 1.10 % 224 1,270 0.98 % 214 > 9 to ≤ 12 months 1,361 1.11 % 284 1,566 1.08 % 299 > 12 to ≤ 24 months 1,588 1.43 % 524 1,203 1.28 % 538 > 24 to ≤ 36 months 2,300 1.50 % 961 1,300 1.36 % 865 > 36 to ≤ 48 months 1,325 1.49 % 1,302 2,200 1.32 % 1,168 > 48 to < 60 months — — % — 625 1.38 % 1,506 Total Agency repo 39,375 1.05 % 176 37,686 0.98 % 187 U.S. Treasury repo: > 1 day to ≤ 1 month — — % — 172 (0.30 )% 17 Total $ 39,375 1.05 % 176 $ 37,858 0.98 % 186 Federal Home Loan Bank Advances As of December 31, 2016 , we had $3.0 billion of outstanding secured Federal Home Loan Bank ("FHLB") advances, with a weighted average borrowing rate of 0.73% . Our FHLB advances matured in February 2017, coinciding with the termination of our wholly-owned captive insurance subsidiary's FHLB membership in February 2017 pursuant to the Federal Housing Finance Agency's ("FHFA") final rule on FHLB membership released in January 2016. As a result, we had no outstanding secured FHLB advances as of March 31, 2017 . Debt of Consolidated Variable Interest Entities As of March 31, 2017 and December 31, 2016 , debt of consolidated VIEs, at fair value, was $434 million and $460 million , respectively, and had a weighted average interest rate of LIBOR plus 37 and 36 basis points, respectively, and a principal balance of $425 million and $452 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 March 31, 2017 and December 31, 2016 was 5.8 years.

Derivative and Other Hedging In

Derivative and Other Hedging Instruments	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative and Other Hedging Instruments	3 to ≤ 5 years 6,250 1.72% 1.06% 4.1 7,450 1.62% 0.91% 4.0 > 5 to ≤ 7 years 3,975 1.82% 1.04% 5.6 4,725 1.89% 0.91% 5.9 > 7 to ≤ 10 years 3,625 1.94% 1.05% 9.1 3,325 1.90% 0.91% 9.2 > 10 years 2,100 2.58% 1.05% 13.5 1,900 2.64% 0.91% 13.8 Total $ 35,775 1.52% 1.06% 3.9 $ 37,175 1.48% 0.92% 3.9 ________________________ 1. As of March 31, 2017 and December 31, 2016 , notional amount includes forward starting swaps of $0.3 billion and $0.6 billion , respectively, with an average forward start date of 2.0 and 1.2 years, respectively, and an average maturity of 12.0 and 10.7 years, respectively. 2. Average fixed pay rate includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.50% and 1.46% as of March 31, 2017 and December 31, 2016 , respectively. 3. Average receive rate excludes forward starting swaps. The following tables summarize certain characteristics of our interest rate payer swaption agreements, U.S. Treasury securities and U.S. Treasury futures outstanding as of March 31, 2017 and December 31, 2016 (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) March 31, 2017 Total ≤ 1 year $ 64 $ 22 8 $ 2,200 3.09% 3M 8.9 December 31, 2016 Total ≤ 1 year $ 52 $ 22 6 $ 1,200 3.06% 3M 8.3 U.S. Treasury Securities March 31, 2017 December 31, 2016 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 ) 7 years (4,135 ) (4,106 ) (4,036 ) (3,056 ) (3,041 ) (2,930 ) 10 years (5,034 ) (4,829 ) (4,756 ) (4,416 ) (4,236 ) (4,132 ) Total U.S. Treasury securities, net $ (9,169 ) $ (8,935 ) $ (8,792 ) $ (7,872 ) $ (7,681 ) $ (7,454 ) U.S. Treasury Futures March 31, 2017 December 31, 2016 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 ) $ (858 ) $ (859 ) $ (1 ) $ (730 ) $ (862 ) $ (859 ) $ 3 10 years (1,080 ) (1,341 ) (1,345 ) (4 ) (1,080 ) (1,347 ) (1,342 ) 5 Total U.S. Treasury futures $ (1,810 ) $ (2,199 ) $ (2,204 ) $ (5 ) $ (1,810 ) $ (2,209 ) $ (2,201 ) $ 8 _____________________ 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 certain characteristics of our TBA securities as of March 31, 2017 and December 31, 2016 (in millions): March 31, 2017 December 31, 2016 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% $ 1,980 $ 1,973 $ 1,978 $ 5 $ 1,853 $ 1,870 $ 1,856 $ (14 ) 3.0% 32 33 33 — 292 302 300 (2 ) 3.5% 139 144 144 — 15 16 16 — Total 15-Year TBA securities 2,151 2,150 2,155 5 2,160 2,188 2,172 (16 ) 30-Year TBA securities: 3.0% 3,686 3,642 3,648 6 3,027 3,114 3,007 (107 ) 3.5% 3,295 3,347 3,369 22 1,209 1,251 1,236 (15 ) 4.0% 5,070 5,273 5,310 37 4,530 4,769 4,760 (9 ) 4.5% (32 ) (35 ) (35 ) — (10 ) (10 ) (10 ) — Total 30-Year TBA securities, net 12,019 12,227 12,292 65 8,756 9,124 8,993 (131 ) Total TBA securities, net $ 14,170 $ 14,377 $ 14,447 $ 70 $ 10,916 $ 11,312 $ 11,165 $ (147 ) March 31, 2017 December 31, 2016 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 $ 12,529 $ 12,720 $ 12,787 $ 67 $ 9,881 $ 10,251 $ 10,118 $ (133 ) Freddie Mac 1,641 1,657 1,660 3 1,035 1,060 1,047 (13 ) Ginnie Mae — — — — — 1 — (1 ) TBA securities, net $ 14,170 $ 14,377 $ 14,447 $ 70 $ 10,916 $ 11,312 $ 11,165 $ (147 ) _____________________ 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 the three months ended March 31, 2017 and 2016 (in millions): Three Months Ended March 31, 2017 Derivative and Other Hedging Instruments Notional Amount December 31, 2016 Additions Settlement, Termination, Expiration or Exercise Notional Amount March 31, 2017 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 10,916 36,096 (32,842 ) $ 14,170 $ 39 Interest rate swaps $ 37,175 1,300 (2,700 ) $ 35,775 22 Payer swaptions $ 1,200 1,000 — $ 2,200 (11 ) U.S. Treasury securities - short position $ (8,061 ) (2,558 ) 1,450 $ (9,169 ) (78 ) U.S. Treasury securities - long position $ 189 303 (492 ) $ — 1 U.S. Treasury futures contracts - short position $ (1,810 ) (1,810 ) 1,810 $ (1,810 ) (12 ) $ (39 ) ________________________________ 1. Excludes a net loss of $1 million from debt of consolidated VIEs recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Three Months Ended March 31, 2016 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount March 31, 2016 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 7,295 17,959 (19,441 ) $ 5,813 $ 216 Interest rate swaps $ 40,525 1,000 (3,350 ) $ 38,175 (1,005 ) Payer swaptions $ 2,150 — (400 ) $ 1,750 (7 ) U.S. Treasury securities - short position $ (1,714 ) (1,980 ) 559 $ (3,135 ) (83 ) U.S. Treasury securities - long position $ 25 180 (205 ) $ — 5 U.S. Treasury futures contracts - short position $ (1,860 ) (1,860 ) 1,860 $ (1,860 ) (77 ) $ (951 ) ______________________ 1. Excludes a net loss of $5 million from debt of consolidated VIEs and other miscellaneous net gains of $12 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 3 . 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 March 31, 2017 and December 31, 2016 (in millions): Derivative and Other Hedging Instruments Balance Sheet Location March 31, 2017 December 31, 2016 Interest rate swaps Derivative assets, at fair value $ 92 $ 321 Swaptions Derivative assets, at fair value 22 22 TBA securities Derivative assets, at fair value 91 4 U.S. Treasury futures - short Derivative assets, at fair value — 8 Total derivative assets, at fair value $ 205 $ 355 Interest rate swaps Derivative liabilities, at fair value $ (43 ) $ (105 ) TBA securities Derivative liabilities, at fair value (21 ) (151 ) U.S. Treasury futures - short Derivative liabilities, at fair value (5 ) — Total derivative liabilities, at fair value $ (69 ) $ (256 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ — $ 182 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (8,792 ) (7,636 ) Total U.S. Treasury securities, net at fair value $ (8,792 ) $ (7,454 ) The following table summarizes certain characteristics of our interest rate swap agreements outstanding as of March 31, 2017 and December 31, 2016 (dollars in millions): March 31, 2017 December 31, 2016 Payer Interest Rate Swaps Notional 1 Average Rate 2 Average 3 Average Notional 1 Average Rate 2 Average 3 Average ≤ 3 years $ 19,825 1.21% 1.06% 1.6 $ 19,775 1.16% 0.92% 1.5 > 3 to ≤ 5 years 6,250 1.72% 1.06% 4.1 7,450 1.62% 0.91% 4.0 > 5 to ≤ 7 years 3,975 1.82% 1.04% 5.6 4,725 1.89% 0.91% 5.9 > 7 to ≤ 10 years 3,625 1.94% 1.05% 9.1 3,325 1.90% 0.91% 9.2 > 10 years 2,100 2.58% 1.05% 13.5 1,900 2.64% 0.91% 13.8 Total $ 35,775 1.52% 1.06% 3.9 $ 37,175 1.48% 0.92% 3.9 ________________________ 1. As of March 31, 2017 and December 31, 2016 , notional amount includes forward starting swaps of $0.3 billion and $0.6 billion , respectively, with an average forward start date of 2.0 and 1.2 years, respectively, and an average maturity of 12.0 and 10.7 years, respectively. 2. Average fixed pay rate includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.50% and 1.46% as of March 31, 2017 and December 31, 2016 , respectively. 3. Average receive rate excludes forward starting swaps. The following tables summarize certain characteristics of our interest rate payer swaption agreements, U.S. Treasury securities and U.S. Treasury futures outstanding as of March 31, 2017 and December 31, 2016 (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) March 31, 2017 Total ≤ 1 year $ 64 $ 22 8 $ 2,200 3.09% 3M 8.9 December 31, 2016 Total ≤ 1 year $ 52 $ 22 6 $ 1,200 3.06% 3M 8.3 U.S. Treasury Securities March 31, 2017 December 31, 2016 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 ) 7 years (4,135 ) (4,106 ) (4,036 ) (3,056 ) (3,041 ) (2,930 ) 10 years (5,034 ) (4,829 ) (4,756 ) (4,416 ) (4,236 ) (4,132 ) Total U.S. Treasury securities, net $ (9,169 ) $ (8,935 ) $ (8,792 ) $ (7,872 ) $ (7,681 ) $ (7,454 ) U.S. Treasury Futures March 31, 2017 December 31, 2016 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 ) $ (858 ) $ (859 ) $ (1 ) $ (730 ) $ (862 ) $ (859 ) $ 3 10 years (1,080 ) (1,341 ) (1,345 ) (4 ) (1,080 ) (1,347 ) (1,342 ) 5 Total U.S. Treasury futures $ (1,810 ) $ (2,199 ) $ (2,204 ) $ (5 ) $ (1,810 ) $ (2,209 ) $ (2,201 ) $ 8 _____________________ 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 certain characteristics of our TBA securities as of March 31, 2017 and December 31, 2016 (in millions): March 31, 2017 December 31, 2016 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% $ 1,980 $ 1,973 $ 1,978 $ 5 $ 1,853 $ 1,870 $ 1,856 $ (14 ) 3.0% 32 33 33 — 292 302 300 (2 ) 3.5% 139 144 144 — 15 16 16 — Total 15-Year TBA securities 2,151 2,150 2,155 5 2,160 2,188 2,172 (16 ) 30-Year TBA securities: 3.0% 3,686 3,642 3,648 6 3,027 3,114 3,007 (107 ) 3.5% 3,295 3,347 3,369 22 1,209 1,251 1,236 (15 ) 4.0% 5,070 5,273 5,310 37 4,530 4,769 4,760 (9 ) 4.5% (32 ) (35 ) (35 ) — (10 ) (10 ) (10 ) — Total 30-Year TBA securities, net 12,019 12,227 12,292 65 8,756 9,124 8,993 (131 ) Total TBA securities, net $ 14,170 $ 14,377 $ 14,447 $ 70 $ 10,916 $ 11,312 $ 11,165 $ (147 ) March 31, 2017 December 31, 2016 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 $ 12,529 $ 12,720 $ 12,787 $ 67 $ 9,881 $ 10,251 $ 10,118 $ (133 ) Freddie Mac 1,641 1,657 1,660 3 1,035 1,060 1,047 (13 ) Ginnie Mae — — — — — 1 — (1 ) TBA securities, net $ 14,170 $ 14,377 $ 14,447 $ 70 $ 10,916 $ 11,312 $ 11,165 $ (147 ) _____________________ 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 the three months ended March 31, 2017 and 2016 (in millions): Three Months Ended March 31, 2017 Derivative and Other Hedging Instruments Notional Amount December 31, 2016 Additions Settlement, Termination, Expiration or Exercise Notional Amount March 31, 2017 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 10,916 36,096 (32,842 ) $ 14,170 $ 39 Interest rate swaps $ 37,175 1,300 (2,700 ) $ 35,775 22 Payer swaptions $ 1,200 1,000 — $ 2,200 (11 ) U.S. Treasury securities - short position $ (8,061 ) (2,558 ) 1,450 $ (9,169 ) (78 ) U.S. Treasury securities - long position $ 189 303 (492 ) $ — 1 U.S. Treasury futures contracts - short position $ (1,810 ) (1,810 ) 1,810 $ (1,810 ) (12 ) $ (39 ) ________________________________ 1. Excludes a net loss of $1 million from debt of consolidated VIEs recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Three Months Ended March 31, 2016 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount March 31, 2016 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 7,295 17,959 (19,441 ) $ 5,813 $ 216 Interest rate swaps $ 40,525 1,000 (3,350 ) $ 38,175 (1,005 ) Payer swaptions $ 2,150 — (400 ) $ 1,750 (7 ) U.S. Treasury securities - short position $ (1,714 ) (1,980 ) 559 $ (3,135 ) (83 ) U.S. Treasury securities - long position $ 25 180 (205 ) $ — 5 U.S. Treasury futures contracts - short position $ (1,860 ) (1,860 ) 1,860 $ (1,860 ) (77 ) $ (951 ) ______________________ 1. Excludes a net loss of $5 million from debt of consolidated VIEs and other miscellaneous net gains of $12 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income.

Pledged Assets

Pledged Assets	3 Months Ended
	Mar. 31, 2017
Pledged Assets [Abstract]
Pledged Assets	30 and ≤ 60 days 5,377 5,415 16 8,103 8,158 23 > 60 and ≤ 90 days 3,448 3,475 10 4,034 4,070 11 > 90 days 13,339 13,448 36 11,278 11,380 32 Total MBS 41,463 41,794 117 43,096 43,471 122 U.S. Treasury securities: > 1 day ≤ 30 days — — — 173 173 — Total $ 41,463 $ 41,794 $ 117 $ 43,269 $ 43,644 $ 122 ______________________ 1. Includes $200 million and $181 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2017 and December 31, 2016 , respectively. As of March 31, 2017 and December 31, 2016 , 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 4 and 5 for additional information regarding our consolidated VIEs. Assets Pledged from Counterparties As of March 31, 2017 and December 31, 2016 , 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). March 31, 2017 December 31, 2016 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 8,839 18 — 8,857 7,636 — — 7,636 Cash — 10 — 10 — 107 — 107 Total $ 8,839 $ 28 $ — $ 8,867 $ 7,636 $ 107 $ 14 $ 7,757 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 March 31, 2017 and December 31, 2016 (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 March 31, 2017 Interest rate swap and swaption agreements, at fair value 1 $ 114 $ — $ 114 $ (31 ) $ (28 ) $ 55 TBA 91 — 91 (21 ) — 70 Receivable under reverse repurchase agreements 8,908 — 8,908 (7,269 ) (1,639 ) — Total $ 9,113 $ — $ 9,113 $ (7,321 ) $ (1,667 ) $ 125 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 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 March 31, 2017 Interest rate swap agreements, at fair value 1 $ 43 $ — $ 43 $ (31 ) $ (12 ) $ — TBA 21 — 21 (21 ) — — Repurchase agreements 39,375 — 39,375 (7,269 ) (32,106 ) — Total $ 39,439 $ — $ 39,439 $ (7,321 ) $ (32,118 ) $ — 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 ) $ — _______________________ 1. Reported under derivative assets/liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 6 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, and the clearing organizations utilized by Bethesda Securities also require that we post minimum daily clearing deposits. If we breach our collateral requirements, we will be required to fully settle our obligations under the agreements, which could include a forced liquidation of our pledged collateral. Our counterparties also apply a "haircut" to our pledged collateral, which means our collateral is valued at slightly less than market value and limits the amount we can borrow against our securities. This haircut reflects the underlying risk of the specific collateral and protects our counterparty against a change in its value. Our agreements do not specify the haircut; rather haircuts are determined on an individual transaction basis. Consequently, our funding agreements and derivative contracts expose us to credit risk relating to potential losses that could be recognized 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 March 31, 2017 , 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 March 31, 2017 and December 31, 2016 , our maximum amount at risk with any counterparty related to our repurchase agreements was 5.2% and 5.5% , respectively, 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 March 31, 2017 and December 31, 2016 (dollars in millions). March 31, 2017 December 31, 2016 Amount Outstanding Net Counterparty Exposure 1 Percent of Equity Weighted Average Months to Maturity Amount Outstanding Net Counterparty Exposure 1 Percent of Equity Weighted Average Months to Maturity J.P. Morgan Securities, LLC $ 4,775 $ 381 5.2 % 32 $ 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 March 31, 2017 and December 31, 2016 (in millions): March 31, 2017 Assets Pledged to Counterparties Repurchase Agreements 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements 2 Total Agency RMBS - fair value $ 41,463 $ 777 $ 259 $ 602 $ 43,101 Non-Agency RMBS - fair value — — — — — U.S. Treasury securities - fair value — — — — — Accrued interest on pledged securities 117 2 1 2 122 Restricted cash and cash equivalents 19 — 150 50 219 Total $ 41,599 $ 779 $ 410 $ 654 $ 43,442 December 31, 2016 Assets Pledged to Counterparties Repurchase Agreements and FHLB Advances 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements 2 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 $200 million and $181 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2017 and December 31, 2016 , respectively. 2. Includes margin for TBAs cleared through prime broker and other clearing deposits. As of December 31, 2016 , we held $126 million of membership and activity-based stock in the FHLB of Des Moines, which was redeemed in February 2017 with the termination of our captive insurance subsidiary's FHLB membership such that we held no such stock as of March 31, 2017 . FHLB stock is reported at cost, which equals par value, in other assets on our accompanying consolidated balance sheets. 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 March 31, 2017 and December 31, 2016 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 5 . March 31, 2017 December 31, 2016 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 $ 19,299 $ 19,456 $ 55 $ 19,681 $ 19,863 $ 56 > 30 and ≤ 60 days 5,377 5,415 16 8,103 8,158 23 > 60 and ≤ 90 days 3,448 3,475 10 4,034 4,070 11 > 90 days 13,339 13,448 36 11,278 11,380 32 Total MBS 41,463 41,794 117 43,096 43,471 122 U.S. Treasury securities: > 1 day ≤ 30 days — — — 173 173 — Total $ 41,463 $ 41,794 $ 117 $ 43,269 $ 43,644 $ 122 ______________________ 1. Includes $200 million and $181 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2017 and December 31, 2016 , respectively. As of March 31, 2017 and December 31, 2016 , 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 4 and 5 for additional information regarding our consolidated VIEs. Assets Pledged from Counterparties As of March 31, 2017 and December 31, 2016 , 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). March 31, 2017 December 31, 2016 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 8,839 18 — 8,857 7,636 — — 7,636 Cash — 10 — 10 — 107 — 107 Total $ 8,839 $ 28 $ — $ 8,867 $ 7,636 $ 107 $ 14 $ 7,757 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 March 31, 2017 and December 31, 2016 (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 March 31, 2017 Interest rate swap and swaption agreements, at fair value 1 $ 114 $ — $ 114 $ (31 ) $ (28 ) $ 55 TBA 91 — 91 (21 ) — 70 Receivable under reverse repurchase agreements 8,908 — 8,908 (7,269 ) (1,639 ) — Total $ 9,113 $ — $ 9,113 $ (7,321 ) $ (1,667 ) $ 125 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 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 March 31, 2017 Interest rate swap agreements, at fair value 1 $ 43 $ — $ 43 $ (31 ) $ (12 ) $ — TBA 21 — 21 (21 ) — — Repurchase agreements 39,375 — 39,375 (7,269 ) (32,106 ) — Total $ 39,439 $ — $ 39,439 $ (7,321 ) $ (32,118 ) $ — 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 ) $ — _______________________ 1. Reported under derivative assets/liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 6 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	3 Months Ended
	Mar. 31, 2017
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 3 . 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 valuation hierarchy levels during the three months ended March 31, 2017 . The three levels of valuation hierarchy are defined as follows: • Level 1 Inputs —Quoted prices (unadjusted) for identical unrestricted assets and liabilities in active markets that are accessible at the measurement date. • Level 2 Inputs —Quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. • Level 3 Inputs —Instruments with primarily unobservable market data that cannot be corroborated. The following table provides a summary of our assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2017 and December 31, 2016 (in millions): March 31, 2017 December 31, 2016 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 43,856 $ — $ — $ 45,393 $ — Agency securities transferred to consolidated VIEs — 777 — — 818 — Non-Agency securities — 31 — — 124 — Credit risk transfer securities — 383 — — 164 — U.S. Treasury securities — — — 182 — — Interest rate swaps — 92 — — 321 — Swaptions — 22 — — 22 — TBA securities — 91 — — 4 — U.S. Treasury futures — — — 8 — — Total $ — $ 45,252 $ — $ 190 $ 46,846 $ — Liabilities: Debt of consolidated VIEs $ — $ 434 $ — $ — $ 460 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 8,792 — — 7,636 — — Interest rate swaps — 43 — — 105 — TBA securities — 21 — — 151 — U.S. Treasury futures 5 — — — — — Total $ 8,797 $ 498 $ — $ 7,636 $ 716 $ — 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.

Net Income (Loss) Per Common Sh

Net Income (Loss) Per Common Share (Notes)	3 Months Ended
	Mar. 31, 2017
Net Income (Loss) Per Common Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended March 31, 2017 2016 Weighted average number of common shares outstanding - basic 331.0 334.4 Unvested restricted stock units and performance share units 0.1 — Weighted average number of common shares outstanding - diluted 331.1 334.4 Net income (loss) available (attributable) to common stockholders $ 69 $ (779 ) Net income (loss) per common share - basic and diluted $ 0.21 $ (2.33 )
Earnings Per Share [Text Block]	Net Income (Loss) Per Common Share Net income (loss) per common share includes no dilution and is computed by dividing net income or (loss) applicable to common stock by the weighted-average number of common shares outstanding for the respective period. Diluted earnings per common share includes the impact of dilutive securities such as unvested restricted stock units and performance share units granted under our long-term incentive program to employees and non-employee Board of Directors. The following table presents the computations of basic and diluted income (loss) per common share for the periods indicated (shares and dollars in millions): Three Months Ended March 31, 2017 2016 Weighted average number of common shares outstanding - basic 331.0 334.4 Unvested restricted stock units and performance share units 0.1 — Weighted average number of common shares outstanding - diluted 331.1 334.4 Net income (loss) available (attributable) to common stockholders $ 69 $ (779 ) Net income (loss) per common share - basic and diluted $ 0.21 $ (2.33 )

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2017
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 March 31, 2017 and December 31, 2016, we had 6.9 million shares of Series A Preferred Stock outstanding and 7.0 million depositary shares outstanding. Each depositary share represents a 1/1,000th interest in a share of our Series B Preferred Stock. As of March 31, 2017 and 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. 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 March 31, 2017 , we had declared all required quarterly dividends on our Series A and Series B Preferred Stock. At-the-Market Offering Program In February 2017, we entered into sales agreements with sales agents to publicly offer and sell shares of our common stock in privately negotiated and/or at-the-market transactions from time-to-time up to an aggregate amount of $750 million of shares of our common stock. During the three months ended March 31, 2017, we did not sell any shares of our common stock under the sales agreements. 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 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. During the three months ended March 31, 2016 , we repurchased 6.5 million shares of our common stock at an average repurchase price of $17.89 , including expenses, totaling $116 million . We did not repurchase shares of our common stock during the three months ended March 31, 2017 . As of March 31, 2017 , the total remaining amount authorized for repurchases of our common stock was $1 billion . Accumulated Other Comprehensive Income (Loss) The following table summarizes changes to accumulated OCI for the three months ended March 31, 2017 and 2016 (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, 2015 $ (27 ) $ (39 ) $ (66 ) OCI before reclassifications 763 — 763 Amounts reclassified from accumulated OCI 2 19 21 Balance as of March 31, 2016 $ 738 $ (20 ) $ 718 Balance as of December 31, 2016 $ (397 ) $ — $ (397 ) OCI before reclassifications (38 ) — (38 ) Amounts reclassified from accumulated OCI 84 — 84 Balance as of March 31, 2017 $ (351 ) $ — $ (351 ) The following table summarizes reclassifications out of accumulated OCI for the three months ended March 31, 2017 and 2016 (in millions): Three Months Ended March 31, Line Item in the Consolidated Statements of Comprehensive Income Where Net Income is Presented Amounts Reclassified from Accumulated OCI 2017 2016 (Gain) loss amounts reclassified from accumulated OCI for available-for-sale MBS upon realization $ 84 $ 2 Realized gain (loss) on sale of investment securities, net Periodic interest costs of interest rate swaps previously designated as hedges under GAAP, net — 19 Interest expense Total reclassifications $ 84 $ 21

Subsequent Event

Subsequent Event	3 Months Ended
	Mar. 31, 2017
Subsequent Events [Abstract]
Subsequent Event	Subsequent Events On April 13, 2017 , our Board of Directors declared a monthly dividend of $0.18 per common share, payable on May 8, 2017 to common stockholders of record as of April 28, 2017 . On May 5, 2017, we completed a follow-on public offering of 24.5 million shares of our common stock for proceeds of $503 million , or $20.53 per common share, net of offering costs. In connection with the offering, we granted the underwriters an option for 30 days to purchase up to an additional 3,675,000 shares of common stock.

Summary of Significant Accoun18

Summary of Significant Accounting Policies (Policy)	3 Months Ended
	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reverse Repurchase Agreements Policy [Policy Text Block]	Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We 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.
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. Mortgage-related securities may also include investments in the common stock of other publicly traded mortgage REITs, including MTGE, which invest in Agency and non-Agency securities and/or other real estate related assets. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities , requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for such securities pursuant to ASC Topic 825, Financial Instruments . All of our securities are reported at fair value as they have either been designated as available-for-sale or trading or we have elected the fair value option of accounting. 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. 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 elected the fair value option to account for CRT, CMBS and Agency interest and principal-only securities and, effective January 1, 2017, for all Agency and non-Agency securities acquired on or after January 1, 2017. In our view, this election simplifies the accounting for such securities and more appropriately reflects the results of our operations for a particular reporting period, as the fair value changes for these assets are 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. Refer to Note 8 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.
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. 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. Our derivative agreements require that we post or receive collateral on such agreements to such risk. We also attempt to minimize our risk of loss 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 was 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 the Chicago Mercantile Exchange ("CME"), a registered commodities exchange. 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. Our centrally cleared swaps require that we post an “initial margin” to our counterparties for an amount determined by the CME, which is generally intended to be set at a level sufficient to protect the CME from the maximum estimated single-day price movement in that market participant’s contracts. We also exchange cash “variation margin” with our counterparties on our centrally cleared swaps based upon daily changes in the fair value as measured by the CME. Beginning in the first quarter of 2017, as a result of a CME amendment to its rule book governing its central clearing activities, the daily exchange of variation margin associated with a CME centrally cleared derivative instrument is legally characterized as the daily settlement of the derivative instrument itself, as opposed to a pledge of collateral. Accordingly, beginning in 2017, we account for the daily receipt or payment of variation margin associated with our centrally cleared interest rate swaps as a direct reduction to the carrying value of the interest rate swap derivative asset or liability, respectively; and the carrying amount of centrally cleared interest rate swaps reflected in our consolidated balance sheets is equal to the unsettled fair value of such instruments. 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.
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 March 31, 2017, we did not accrue a loss contingency related to these matters.

Summary of Significant Accoun19

Summary of Significant Accounting Policies Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2017
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. Our derivative agreements require that we post or receive collateral on such agreements to such risk. We also attempt to minimize our risk of loss 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 was 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 the Chicago Mercantile Exchange ("CME"), a registered commodities exchange. 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. Our centrally cleared swaps require that we post an “initial margin” to our counterparties for an amount determined by the CME, which is generally intended to be set at a level sufficient to protect the CME from the maximum estimated single-day price movement in that market participant’s contracts. We also exchange cash “variation margin” with our counterparties on our centrally cleared swaps based upon daily changes in the fair value as measured by the CME. Beginning in the first quarter of 2017, as a result of a CME amendment to its rule book governing its central clearing activities, the daily exchange of variation margin associated with a CME centrally cleared derivative instrument is legally characterized as the daily settlement of the derivative instrument itself, as opposed to a pledge of collateral. Accordingly, beginning in 2017, we account for the daily receipt or payment of variation margin associated with our centrally cleared interest rate swaps as a direct reduction to the carrying value of the interest rate swap derivative asset or liability, respectively; and the carrying amount of centrally cleared interest rate swaps reflected in our consolidated balance sheets is equal to the unsettled fair value of such instruments. 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. Mortgage-related securities may also include investments in the common stock of other publicly traded mortgage REITs, including MTGE, which invest in Agency and non-Agency securities and/or other real estate related assets. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities , requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for such securities pursuant to ASC Topic 825, Financial Instruments . All of our securities are reported at fair value as they have either been designated as available-for-sale or trading or we have elected the fair value option of accounting. 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. 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 elected the fair value option to account for CRT, CMBS and Agency interest and principal-only securities and, effective January 1, 2017, for all Agency and non-Agency securities acquired on or after January 1, 2017. In our view, this election simplifies the accounting for such securities and more appropriately reflects the results of our operations for a particular reporting period, as the fair value changes for these assets are 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. Refer to Note 8 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.
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. 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.

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Securities by Credit Rating [Table Text Block]	As of March 31, 2017 and December 31, 2016 , our investments in non-Agency securities had the following credit ratings: March 31, 2017 December 31, 2016 Non-Agency Security Credit Ratings 1 CRT RMBS CMBS CRT RMBS CMBS AAA $ — $ 8 $ — $ — $ 99 $ — BBB — — 23 — — 23 BB 31 — — — — — B 350 — — 164 2 — Not Rated 2 — — — — — Total $ 383 $ 8 $ 23 $ 164 $ 101 $ 23 ________________________ 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 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 . March 31, 2017 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 28,651 $ 8,986 $ 41 $ 8 $ — $ — $ 37,686 Unamortized discount (27 ) (3 ) — — — — (30 ) Unamortized premium 1,325 489 1 — — — 1,815 Amortized cost 29,949 9,472 42 8 — — 39,471 Gross unrealized gains 156 49 1 — — — 206 Gross unrealized losses (393 ) (164 ) — — — — (557 ) Total available-for-sale securities, at fair value 29,712 9,357 43 8 — — 39,120 Securities remeasured at fair value through earnings: Par value 1 5,198 26 — — 24 364 5,612 Unamortized discount (40 ) — — — (1 ) — (41 ) Unamortized premium 286 14 — — — 11 311 Amortized cost 5,444 40 — — 23 375 5,882 Gross unrealized gains 40 3 — — — 8 51 Gross unrealized losses (5 ) (1 ) — — — — (6 ) Total securities remeasured at fair value through earnings 5,479 42 — — 23 383 5,927 Total securities, at fair value $ 35,191 $ 9,399 $ 43 $ 8 $ 23 $ 383 $ 45,047 Weighted average coupon as of March 31, 2017 3.65 % 3.68 % 2.76 % 2.50 % 6.55 % 5.17 % 3.67 % Weighted average yield as of March 31, 2017 2 2.83 % 2.71 % 2.00 % 2.97 % 7.54 % 5.85 % 2.83 % ________________________ 1. Par value amount excludes the underlying unamortized principal balance ("UPB") of interest-only securities of $0.9 billion as of March 31, 2017 . 2. Incorporates a weighted average future constant prepayment rate assumption of 8% based on forward rates as of March 31, 2017 .
Components of Investment Securities	The following tables summarize our investment securities as of March 31, 2017 and December 31, 2016 (dollars in millions): March 31, 2017 December 31, 2016 Investment Securities Amortized Cost Fair Value Amortized Fair Value Agency RMBS: Fixed rate $ 43,585 $ 43,232 $ 45,145 $ 44,736 Adjustable rate 354 362 371 379 CMO 755 761 796 801 Interest-only and principal-only strips 254 278 268 295 Total Agency RMBS 44,948 44,633 46,580 46,211 Non-Agency RMBS 8 8 102 101 CMBS 23 23 23 23 CRT securities 375 383 161 164 Total investment securities $ 45,354 $ 45,047 $ 46,866 $ 46,499 March 31, 2017 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 28,651 $ 8,986 $ 41 $ 8 $ — $ — $ 37,686 Unamortized discount (27 ) (3 ) — — — — (30 ) Unamortized premium 1,325 489 1 — — — 1,815 Amortized cost 29,949 9,472 42 8 — — 39,471 Gross unrealized gains 156 49 1 — — — 206 Gross unrealized losses (393 ) (164 ) — — — — (557 ) Total available-for-sale securities, at fair value 29,712 9,357 43 8 — — 39,120 Securities remeasured at fair value through earnings: Par value 1 5,198 26 — — 24 364 5,612 Unamortized discount (40 ) — — — (1 ) — (41 ) Unamortized premium 286 14 — — — 11 311 Amortized cost 5,444 40 — — 23 375 5,882 Gross unrealized gains 40 3 — — — 8 51 Gross unrealized losses (5 ) (1 ) — — — — (6 ) Total securities remeasured at fair value through earnings 5,479 42 — — 23 383 5,927 Total securities, at fair value $ 35,191 $ 9,399 $ 43 $ 8 $ 23 $ 383 $ 45,047 Weighted average coupon as of March 31, 2017 3.65 % 3.68 % 2.76 % 2.50 % 6.55 % 5.17 % 3.67 % Weighted average yield as of March 31, 2017 2 2.83 % 2.71 % 2.00 % 2.97 % 7.54 % 5.85 % 2.83 %
Summary Of Agency Securities Estimated Weighted Average Life Classifications	The following table summarizes our investments classified as available-for-sale as of March 31, 2017 and December 31, 2016 according to their estimated weighted average life classification (dollars in millions): March 31, 2017 December 31, 2016 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 $ 747 $ 736 3.90% 2.55% $ 414 $ 410 3.99% 2.52% > 3 years and ≤ 5 years 11,717 11,628 3.30% 2.42% 13,534 13,449 3.26% 2.40% > 5 years and ≤10 years 26,130 26,579 3.67% 2.85% 30,226 30,713 3.65% 2.86% > 10 years 526 528 3.08% 3.06% 1,843 1,842 3.02% 3.07% Total $ 39,120 $ 39,471 3.55% 2.72% $ 46,017 $ 46,414 3.52% 2.73%
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 March 31, 2017 and December 31, 2016 (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 March 31, 2017 $ 24,113 $ (490 ) $ 1,646 $ (67 ) $ 25,759 $ (557 ) December 31, 2016 $ 28,397 $ (554 ) $ 1,719 $ (68 ) $ 30,116 $ (622 )
Summary of Net Gain from Sale of Agency Securities	The following table is a summary of our net gain (loss) from the sale of investment securities for the three months ended March 31, 2017 and 2016 by investment classification of accounting (see Note 3 ) (in millions). Three Months Ended March 31, 2017 2016 Investment Securities Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale Securities 2 Fair Value Option Securities Total Investment securities sold, at cost $ (5,149 ) $ (26 ) $ (5,175 ) $ (3,515 ) $ — $ (3,515 ) Proceeds from investment securities sold 1 5,065 26 5,091 3,513 — 3,513 Net gain (loss) on sale of investment securities $ (84 ) $ — $ (84 ) $ (2 ) $ — $ (2 ) Gross gain on sale of investment securities $ 4 $ — $ 4 $ 5 $ — $ 5 Gross loss on sale of investment securities (88 ) — (88 ) (7 ) — (7 ) Net gain (loss) on sale of investment securities $ (84 ) $ — $ (84 ) $ (2 ) $ — $ (2 ) ________________________ 1. Proceeds include cash received during the period, plus receivable for investment securities sold during the period as of period end. 2. See Note 10 for a summary of changes in accumulated OCI.

Repurchase Agreements and Oth21

Repurchase Agreements and Other Debt (Tables)	3 Months Ended
	Mar. 31, 2017
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 March 31, 2017 and December 31, 2016 (dollars in millions): March 31, 2017 December 31, 2016 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 $ 18,574 0.94 % 13 $ 17,481 0.90 % 11 > 1 to ≤ 3 months 8,728 1.02 % 55 10,011 0.93 % 55 > 3 to ≤ 6 months 1,831 0.97 % 121 2,030 1.02 % 136 > 6 to ≤ 9 months 3,668 1.10 % 224 1,270 0.98 % 214 > 9 to ≤ 12 months 1,361 1.11 % 284 1,566 1.08 % 299 > 12 to ≤ 24 months 1,588 1.43 % 524 1,203 1.28 % 538 > 24 to ≤ 36 months 2,300 1.50 % 961 1,300 1.36 % 865 > 36 to ≤ 48 months 1,325 1.49 % 1,302 2,200 1.32 % 1,168 > 48 to < 60 months — — % — 625 1.38 % 1,506 Total Agency repo 39,375 1.05 % 176 37,686 0.98 % 187 U.S. Treasury repo: > 1 day to ≤ 1 month — — % — 172 (0.30 )% 17 Total $ 39,375 1.05 % 176 $ 37,858 0.98 % 186
Schedule of Federal Home Loan Bank Advances and Weighted Average Interest Rates [Table Text Block]	As of December 31, 2016 , we had $3.0 billion of outstanding secured Federal Home Loan Bank ("FHLB") advances, with a weighted average borrowing rate of 0.73% . Our FHLB advances matured in February 2017, coinciding with the termination of our wholly-owned captive insurance subsidiary's FHLB membership in February 2017 pursuant to the Federal Housing Finance Agency's ("FHFA") final rule on FHLB membership released in January 2016. As a result, we had no outstanding secured FHLB advances as of March 31, 2017 .

Derivative and Other Hedging 22

Derivative and Other Hedging Instruments (Tables)	3 Months Ended
	Mar. 31, 2017
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 March 31, 2017 and December 31, 2016 (in millions): Derivative and Other Hedging Instruments Balance Sheet Location March 31, 2017 December 31, 2016 Interest rate swaps Derivative assets, at fair value $ 92 $ 321 Swaptions Derivative assets, at fair value 22 22 TBA securities Derivative assets, at fair value 91 4 U.S. Treasury futures - short Derivative assets, at fair value — 8 Total derivative assets, at fair value $ 205 $ 355 Interest rate swaps Derivative liabilities, at fair value $ (43 ) $ (105 ) TBA securities Derivative liabilities, at fair value (21 ) (151 ) U.S. Treasury futures - short Derivative liabilities, at fair value (5 ) — Total derivative liabilities, at fair value $ (69 ) $ (256 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ — $ 182 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (8,792 ) (7,636 ) Total U.S. Treasury securities, net at fair value $ (8,792 ) $ (7,454 )
Schedule of Interest Rate Swaption Agreements Outstanding	The following tables summarize certain characteristics of our interest rate payer swaption agreements, U.S. Treasury securities and U.S. Treasury futures outstanding as of March 31, 2017 and December 31, 2016 (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) March 31, 2017 Total ≤ 1 year $ 64 $ 22 8 $ 2,200 3.09% 3M 8.9 December 31, 2016 Total ≤ 1 year $ 52 $ 22 6 $ 1,200 3.06% 3M 8.3 U.S. Treasury Securities March 31, 2017 December 31, 2016 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 ) 7 years (4,135 ) (4,106 ) (4,036 ) (3,056 ) (3,041 ) (2,930 ) 10 years (5,034 ) (4,829 ) (4,756 ) (4,416 ) (4,236 ) (4,132 ) Total U.S. Treasury securities, net $ (9,169 ) $ (8,935 ) $ (8,792 ) $ (7,872 ) $ (7,681 ) $ (7,454 )
US government securities	U.S. Treasury Securities March 31, 2017 December 31, 2016 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 ) 7 years (4,135 ) (4,106 ) (4,036 ) (3,056 ) (3,041 ) (2,930 ) 10 years (5,034 ) (4,829 ) (4,756 ) (4,416 ) (4,236 ) (4,132 ) Total U.S. Treasury securities, net $ (9,169 ) $ (8,935 ) $ (8,792 ) $ (7,872 ) $ (7,681 ) $ (7,454 )
US Government Futures Securities [Table Text Block]	U.S. Treasury Futures March 31, 2017 December 31, 2016 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 ) $ (858 ) $ (859 ) $ (1 ) $ (730 ) $ (862 ) $ (859 ) $ 3 10 years (1,080 ) (1,341 ) (1,345 ) (4 ) (1,080 ) (1,347 ) (1,342 ) 5 Total U.S. Treasury futures $ (1,810 ) $ (2,199 ) $ (2,204 ) $ (5 ) $ (1,810 ) $ (2,209 ) $ (2,201 ) $ 8 _____________________ 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 certain characteristics of our TBA securities as of March 31, 2017 and December 31, 2016 (in millions): March 31, 2017 December 31, 2016 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% $ 1,980 $ 1,973 $ 1,978 $ 5 $ 1,853 $ 1,870 $ 1,856 $ (14 ) 3.0% 32 33 33 — 292 302 300 (2 ) 3.5% 139 144 144 — 15 16 16 — Total 15-Year TBA securities 2,151 2,150 2,155 5 2,160 2,188 2,172 (16 ) 30-Year TBA securities: 3.0% 3,686 3,642 3,648 6 3,027 3,114 3,007 (107 ) 3.5% 3,295 3,347 3,369 22 1,209 1,251 1,236 (15 ) 4.0% 5,070 5,273 5,310 37 4,530 4,769 4,760 (9 ) 4.5% (32 ) (35 ) (35 ) — (10 ) (10 ) (10 ) — Total 30-Year TBA securities, net 12,019 12,227 12,292 65 8,756 9,124 8,993 (131 ) Total TBA securities, net $ 14,170 $ 14,377 $ 14,447 $ 70 $ 10,916 $ 11,312 $ 11,165 $ (147 ) March 31, 2017 December 31, 2016 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 $ 12,529 $ 12,720 $ 12,787 $ 67 $ 9,881 $ 10,251 $ 10,118 $ (133 ) Freddie Mac 1,641 1,657 1,660 3 1,035 1,060 1,047 (13 ) Ginnie Mae — — — — — 1 — (1 ) TBA securities, net $ 14,170 $ 14,377 $ 14,447 $ 70 $ 10,916 $ 11,312 $ 11,165 $ (147 ) _____________________ 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 the three months ended March 31, 2017 and 2016 (in millions): Three Months Ended March 31, 2017 Derivative and Other Hedging Instruments Notional Amount December 31, 2016 Additions Settlement, Termination, Expiration or Exercise Notional Amount March 31, 2017 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 10,916 36,096 (32,842 ) $ 14,170 $ 39 Interest rate swaps $ 37,175 1,300 (2,700 ) $ 35,775 22 Payer swaptions $ 1,200 1,000 — $ 2,200 (11 ) U.S. Treasury securities - short position $ (8,061 ) (2,558 ) 1,450 $ (9,169 ) (78 ) U.S. Treasury securities - long position $ 189 303 (492 ) $ — 1 U.S. Treasury futures contracts - short position $ (1,810 ) (1,810 ) 1,810 $ (1,810 ) (12 ) $ (39 ) ________________________________ 1. Excludes a net loss of $1 million from debt of consolidated VIEs recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Three Months Ended March 31, 2016 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount March 31, 2016 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 7,295 17,959 (19,441 ) $ 5,813 $ 216 Interest rate swaps $ 40,525 1,000 (3,350 ) $ 38,175 (1,005 ) Payer swaptions $ 2,150 — (400 ) $ 1,750 (7 ) U.S. Treasury securities - short position $ (1,714 ) (1,980 ) 559 $ (3,135 ) (83 ) U.S. Treasury securities - long position $ 25 180 (205 ) $ — 5 U.S. Treasury futures contracts - short position $ (1,860 ) (1,860 ) 1,860 $ (1,860 ) (77 ) $ (951 ) ______________________ 1. Excludes a net loss of $5 million from debt of consolidated VIEs and other miscellaneous net gains of $12 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 certain characteristics of our interest rate swap agreements outstanding as of March 31, 2017 and December 31, 2016 (dollars in millions): March 31, 2017 December 31, 2016 Payer Interest Rate Swaps Notional 1 Average Rate 2 Average 3 Average Notional 1 Average Rate 2 Average 3 Average ≤ 3 years $ 19,825 1.21% 1.06% 1.6 $ 19,775 1.16% 0.92% 1.5 > 3 to ≤ 5 years 6,250 1.72% 1.06% 4.1 7,450 1.62% 0.91% 4.0 > 5 to ≤ 7 years 3,975 1.82% 1.04% 5.6 4,725 1.89% 0.91% 5.9 > 7 to ≤ 10 years 3,625 1.94% 1.05% 9.1 3,325 1.90% 0.91% 9.2 > 10 years 2,100 2.58% 1.05% 13.5 1,900 2.64% 0.91% 13.8 Total $ 35,775 1.52% 1.06% 3.9 $ 37,175 1.48% 0.92% 3.9 ________________________

Pledged Assets (Tables)

Pledged Assets (Tables)	3 Months Ended
	Mar. 31, 2017
Pledged Assets [Abstract]
Schedule of Securities and Cash Pledged as Collateral from Counterparties [Table Text Block]	As of March 31, 2017 and December 31, 2016 , 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). March 31, 2017 December 31, 2016 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 8,839 18 — 8,857 7,636 — — 7,636 Cash — 10 — 10 — 107 — 107 Total $ 8,839 $ 28 $ — $ 8,867 $ 7,636 $ 107 $ 14 $ 7,757
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 March 31, 2017 and December 31, 2016 (in millions): March 31, 2017 Assets Pledged to Counterparties Repurchase Agreements 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements 2 Total Agency RMBS - fair value $ 41,463 $ 777 $ 259 $ 602 $ 43,101 Non-Agency RMBS - fair value — — — — — U.S. Treasury securities - fair value — — — — — Accrued interest on pledged securities 117 2 1 2 122 Restricted cash and cash equivalents 19 — 150 50 219 Total $ 41,599 $ 779 $ 410 $ 654 $ 43,442 December 31, 2016 Assets Pledged to Counterparties Repurchase Agreements and FHLB Advances 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements 2 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 $200 million and $181 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2017 and December 31, 2016 , respectively. 2. Includes margin for TBAs cleared through prime broker and other clearing deposits.
Schedules Of Securities Pledged As Collateral Under Repurchase Agreement	The following table summarizes our securities pledged as collateral under our repurchase agreements and FHLB advances by the remaining maturity of our borrowings, including securities pledged related to sold but not yet settled securities, as of March 31, 2017 and December 31, 2016 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 5 . March 31, 2017 December 31, 2016 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 $ 19,299 $ 19,456 $ 55 $ 19,681 $ 19,863 $ 56 > 30 and ≤ 60 days 5,377 5,415 16 8,103 8,158 23 > 60 and ≤ 90 days 3,448 3,475 10 4,034 4,070 11 > 90 days 13,339 13,448 36 11,278 11,380 32 Total MBS 41,463 41,794 117 43,096 43,471 122 U.S. Treasury securities: > 1 day ≤ 30 days — — — 173 173 — Total $ 41,463 $ 41,794 $ 117 $ 43,269 $ 43,644 $ 122 ______________________ 1. Includes $200 million and $181 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2017 and December 31, 2016 , 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 March 31, 2017 and December 31, 2016 (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 March 31, 2017 Interest rate swap and swaption agreements, at fair value 1 $ 114 $ — $ 114 $ (31 ) $ (28 ) $ 55 TBA 91 — 91 (21 ) — 70 Receivable under reverse repurchase agreements 8,908 — 8,908 (7,269 ) (1,639 ) — Total $ 9,113 $ — $ 9,113 $ (7,321 ) $ (1,667 ) $ 125 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
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 March 31, 2017 Interest rate swap agreements, at fair value 1 $ 43 $ — $ 43 $ (31 ) $ (12 ) $ — TBA 21 — 21 (21 ) — — Repurchase agreements 39,375 — 39,375 (7,269 ) (32,106 ) — Total $ 39,439 $ — $ 39,439 $ (7,321 ) $ (32,118 ) $ — 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 ) $ — _______________________ 1. Reported under derivative assets/liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 6 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)	3 Months Ended
	Mar. 31, 2017
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 March 31, 2017 and December 31, 2016 (in millions): March 31, 2017 December 31, 2016 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 43,856 $ — $ — $ 45,393 $ — Agency securities transferred to consolidated VIEs — 777 — — 818 — Non-Agency securities — 31 — — 124 — Credit risk transfer securities — 383 — — 164 — U.S. Treasury securities — — — 182 — — Interest rate swaps — 92 — — 321 — Swaptions — 22 — — 22 — TBA securities — 91 — — 4 — U.S. Treasury futures — — — 8 — — Total $ — $ 45,252 $ — $ 190 $ 46,846 $ — Liabilities: Debt of consolidated VIEs $ — $ 434 $ — $ — $ 460 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 8,792 — — 7,636 — — Interest rate swaps — 43 — — 105 — TBA securities — 21 — — 151 — U.S. Treasury futures 5 — — — — — Total $ 8,797 $ 498 $ — $ 7,636 $ 716 $ —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes changes to accumulated OCI for the three months ended March 31, 2017 and 2016 (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, 2015 $ (27 ) $ (39 ) $ (66 ) OCI before reclassifications 763 — 763 Amounts reclassified from accumulated OCI 2 19 21 Balance as of March 31, 2016 $ 738 $ (20 ) $ 718 Balance as of December 31, 2016 $ (397 ) $ — $ (397 ) OCI before reclassifications (38 ) — (38 ) Amounts reclassified from accumulated OCI 84 — 84 Balance as of March 31, 2017 $ (351 ) $ — $ (351 ) The following table summarizes reclassifications out of accumulated OCI for the three months ended March 31, 2017 and 2016 (in millions): Three Months Ended March 31, Line Item in the Consolidated Statements of Comprehensive Income Where Net Income is Presented Amounts Reclassified from Accumulated OCI 2017 2016 (Gain) loss amounts reclassified from accumulated OCI for available-for-sale MBS upon realization $ 84 $ 2 Realized gain (loss) on sale of investment securities, net Periodic interest costs of interest rate swaps previously designated as hedges under GAAP, net — 19 Interest expense Total reclassifications $ 84 $ 21

Organization (Details)

Organization (Details)	3 Months Ended
	Mar. 31, 2017
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 Accoun27

Summary of Significant Accounting Policies (Details)	3 Months Ended
	Mar. 31, 2017
Derivative [Line Items]
Required Annual Distribution of Taxable Net Income	90.00%

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	$ 45,047		$ 46,499
Weighted average expected constant prepayment rate	8.00%		8.00%
Agency securities, total fair value	$ 800
Debt, at fair value	434		$ 460
Principal balance of agency securities collaterizing debt issued by securitization trust	(700)		(800)
Principal amount	425		452
Gain (loss) associated with consolidated debt	(1)	$ (5)
Fair value of CMO securities and interest-only and principal-only strips	1,000		1,100
Securitized CMO Securities	1,400		1,500
CMO and Interest Only, Principal Only Securities, Maximum Loss Exposure	167		182
Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unamortized premium balance	2,100
TBA securities Fifteen Year and Thirty Year Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Net long TBA position, at fair value	14,400		11,200
TBA, net carrying value	$ 70		$ (147)
Credit Risk Transfer Securities [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	4.30%		4.60%
Underlying Collateral Coupon	3.60%		4.00%
Credit Risk Transfer Securities [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted Average Coupon Rate	7.30%		7.10%
Underlying Collateral Coupon	4.20%		4.20%

Investment Securities (Summary

Investment Securities (Summary of Investment in Agency Security) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Amortized cost	$ 39,471	$ 46,414
Mortgage Backed Securities Amortized Cost	45,354	46,866
Fair value	39,120	46,017
Total agency MBS, amortized cost	44,948	46,580
Total agency MBS, at fair value	44,633	46,211
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	45,047	46,499
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Amortized cost	8	102
Fair value	8	101
Commercial Mortgage Backed Securities [Member]
Amortized cost	23	23
Fair value	23	23
Credit Risk Transfer Securities [Member]
Interest-only and principal-only strips, amortized cost	375	161
Interest-only and principal-only strips, fair value	383	164
Fixed Income Securities [Member] | Agency Securities [Member]
Amortized cost	43,585	45,145
Fair value	43,232	44,736
Adjustable-Rate [Member] | Agency Securities [Member]
Amortized cost	354	371
Fair value	362	379
Collateralized Mortgage Obligations [Member] | Agency Securities [Member]
Amortized cost	755	796
Fair value	761	801
Interest Only And Principal Only Strip [Member] | Agency Securities [Member]
Interest-only and principal-only strips, amortized cost	254	268
Interest-only and principal-only strips, fair value	$ 278	$ 295

Investment Securities (Componen

Investment Securities (Components Of Investment Securities) (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Mar. 31, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Agency securities transferred to consolidated VIEs		$ 777	$ 818
Amortized cost		39,471	46,414
Total agency MBS, at fair value		44,633	46,211
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure		$ 45,047	$ 46,499
Weighted average coupon		3.67%	3.61%
Weighted average yield		2.83%	2.77%	[1]
Unamortized Principal Balance Of Interest Only Strips		$ 900	$ 900
Future Prepayment Rate Assumption Of Investment Portfolio		8.00%	8.00%
Mortgage Backed Securities Amortized Cost		$ 45,354	$ 46,866
Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		37,686	44,397
Unamortized discount		(30)	(46)
Unamortized premium		1,815	2,063
Amortized cost		39,471	46,414
Gross unrealized gains		206	225
Gross unrealized losses		(557)	(622)
Total available-for-sale securities, at fair value		39,120	46,017
Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Securities Remeasured at Fair Value through earnings, Amortized Cost		5,882	452
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		51	34
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		(6)	(4)
Securities Remeasured at Fair Value Through Earnings, Debt Securities		5,927	482
Securities remeasured at fair value through earnings, Par Value		5,612	352
Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		(41)	(36)
Unamortized premium		311	136
Fannie Mae [Member]
Schedule of Investments [Line Items]
Total agency MBS, at fair value		$ 35,191	$ 35,732
Weighted average coupon		3.65%	3.59%
Weighted average yield	[1]	2.83%	2.77%
Fannie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 28,651	$ 34,244
Unamortized discount		(27)	(43)
Unamortized premium		1,325	1,518
Amortized cost		29,949	35,719
Gross unrealized gains		156	176
Gross unrealized losses		(393)	(442)
Total available-for-sale securities, at fair value		29,712	35,453
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		5,444	254
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		40	28
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		(5)	(3)
Securities Remeasured at Fair Value Through Earnings, Debt Securities		5,479	279
Securities remeasured at fair value through earnings, Par Value		5,198	171
Fannie Mae [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		(40)	(35)
Unamortized premium		286	118
Freddie Mac [Member]
Schedule of Investments [Line Items]
Total agency MBS, at fair value		$ 9,399	$ 10,434
Weighted average coupon		3.68%	3.67%
Weighted average yield	[1]	2.71%	2.72%
Freddie Mac [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 8,986	$ 10,008
Unamortized discount		(3)	(3)
Unamortized premium		489	544
Amortized cost		9,472	10,549
Gross unrealized gains		49	48
Gross unrealized losses		(164)	(179)
Total available-for-sale securities, at fair value		9,357	10,418
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		40	14
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		3	3
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		(1)	(1)
Securities Remeasured at Fair Value Through Earnings, Debt Securities		42	16
Securities remeasured at fair value through earnings, Par Value		26	0
Freddie Mac [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		0	0
Unamortized premium		14	14
Ginnie Mae [Member]
Schedule of Investments [Line Items]
Total agency MBS, at fair value		$ 43	$ 45
Weighted average coupon		2.76%	2.75%
Weighted average yield	[1]	2.00%	2.00%
Ginnie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 41	$ 44
Unamortized discount		0	0
Unamortized premium		1	0
Amortized cost		42	44
Gross unrealized gains		1	1
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		43	45
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		8	102
Total Securities		$ 8	$ 101
Weighted average coupon		2.50%	3.42%
Weighted average yield	[1]	2.97%	3.27%
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 8	$ 101
Unamortized discount		0	0
Unamortized premium		0	1
Amortized cost		8	102
Gross unrealized gains		0	0
Gross unrealized losses		0	(1)
Total available-for-sale securities, at fair value		8	101
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	23
Total Securities		$ 23	$ 23
Weighted average coupon		6.55%	6.55%
Weighted average yield	[1]	7.54%	7.54%
Commercial Mortgage Backed Securities [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		$ 0	$ 0
Unamortized discount		0	0
Unamortized premium		0	0
Amortized cost		0	0
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		0	0
Commercial Mortgage Backed Securities [Member] | Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Securities Remeasured at Fair Value through earnings, Amortized Cost		23	23
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		23	23
Securities remeasured at fair value through earnings, Par Value		24	24
Commercial Mortgage Backed Securities [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		(1)	(1)
Unamortized premium		0	0
Credit Risk Transfer Securities [Member]
Schedule of Investments [Line Items]
Trading Securities, Cost		$ 375	$ 161
Weighted average coupon		5.17%	5.25%
Weighted average yield		5.85%	6.28%
Trading Securities, Other		$ 383	$ 164
Credit Risk Transfer Securities [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value		0	0
Unamortized discount		0	0
Unamortized premium		0	0
Amortized cost		0	0
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total available-for-sale securities, at fair value		0	0
Credit Risk Transfer Securities [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Unamortized discount		0	0
Unamortized premium		11	4
Securities Remeasured at Fair Value through earnings, Amortized Cost		375	161
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Gain		8	3
Securities Remeasured at Fair Value Through Earnings, Gross Unrealized Loss		0	0
Securities Remeasured at Fair Value Through Earnings, Debt Securities		383	164
Securities remeasured at fair value through earnings, Par Value		364	157
Total Securities		$ 383	$ 164
[1]	Incorporates a weighted average future constant prepayment rate assumption of 8% based on forward rates as of March 31, 2017

Investment Securities (Summar31

Investment Securities (Summary Of Agency Securities Estimated Weighted Average Life Classifications) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Agency securities classified as available for sale, Fair value	$ 39,120	$ 46,017
Agency securities classified as available for sale, Amortized cost	$ 39,471	$ 46,414
Weighted Average Coupon	3.55%	3.52%
Weighted Average Yield	2.72%	2.73%
Greater Than One Year and Less Than or Equal to Three Years [Member]
Fair Value	$ 747	$ 414
Amortized Cost	$ 736	$ 410
Weighted Average Coupon	3.90%	3.99%
Weighted Average Yield	2.55%	2.52%
Greater Than Three Years and Less Than or Equal to Five Years [Member]
Fair Value	$ 11,717	$ 13,534
Amortized Cost	$ 11,628	$ 13,449
Weighted Average Coupon	3.30%	3.26%
Weighted Average Yield	2.42%	2.40%
Greater Than Five Years [Member]
Fair Value	$ 26,130	$ 30,226
Amortized Cost	$ 26,579	$ 30,713
Weighted Average Coupon	3.67%	3.65%
Weighted Average Yield	2.85%	2.86%
Greater Than Ten Years [Member]
Fair Value	$ 526	$ 1,843
Amortized Cost	$ 528	$ 1,842
Weighted Average Coupon	3.08%	3.02%
Weighted Average Yield	3.06%	3.07%

Investment Securities (Summar32

Investment Securities (Summary Of Changes In Accumulated OCI For Available-For-Sale Security) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Unrealized Gains and (Losses), Net	$ 46	$ 765
Agency Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning OCI Balance	(397)	(27)
Unrealized Gains and (Losses), Net	(38)	763
Reversal of Unrealized (Gains) and Losses, Net on Realization	84	2
Ending OCI Balance	$ (351)	$ 738

Investment Securities (Summar33

Investment Securities (Summary Of Continuous Unrealized Loss Positions Of Available-For-Sale Security) (Details) - Accumulated Other Comprehensive Income (Loss) [Member] - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Unrealized Loss Position For - Estimated Fair Value - Less than 12 Months	$ 24,113	$ 28,397
Unrealized Loss Position For - Unrealized Loss - Less than 12 Months	(490)	(554)
Unrealized Loss Position For - Estimated Fair Value - 12 Months or More	1,646	1,719
Unrealized Loss Position For - Unrealized Loss - 12 Months or More	(67)	(68)
Unrealized Loss Position For - Estimated Fair Value - Total	25,759	30,116
Unrealized Loss Position For - Unrealized Loss - Total	$ (557)	$ (622)

Investment Securities (Summar34

Investment Securities (Summary Of Net Gain From Sale Of Agency Securities) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Gain Loss on Other Debt	$ (1)	$ (5)
Cost of Sale of Fair Value Option Securities	(26)	0
Cost of Sale of Investment Securities	(5,175)	(3,515)
Proceeds from agency MBS sold	2,999	2,164
Net gain (loss) on sale of investment securities	(84)	(2)
Available-for-sale Securities [Member]
Agency MBS sold, at cost	(5,149)	(3,515)
Proceeds from agency MBS sold	5,065	3,513
Net gain (loss) on sale of investment securities	(84)	(2)
Gross gain on sale of investment securities	4	5
Gross loss on sale of investment securities	(88)	(7)
Securities Remeasured at Fair Value [Member]
Proceeds from agency MBS sold	26	0
Net gain (loss) on sale of investment securities	0	0
Gross gain on sale of investment securities	0	0
Gross loss on sale of investment securities	0	0
Securities (Assets) [Member]
Proceeds from agency MBS sold	5,091	3,513
Net gain (loss) on sale of investment securities	(84)	(2)
Gross gain on sale of investment securities	4	5
Gross loss on sale of investment securities	$ (88)	$ (7)

Investment Securities Securitie

Investment Securities Securities by Credit Rating (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
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	$ 383	$ 164
Available-for-sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Securities	39,120	46,017
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	8	101
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	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	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	5,927	482
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	23
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	23
BB Rating [Member] | Credit Risk Transfer Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	31
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	8	99
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	0	2
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	350	$ 164
Not Rated [Member] | Credit Risk Transfer Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Remeasured at Fair Value Through Earnings, Debt Securities	$ 2

Repurchase Agreements And Oth36

Repurchase Agreements And Other Debt (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	$ 39,375	$ 37,858
Debt of consolidated variable interest entities, at fair value	$ 434	$ 460
Description of variable rate basis	LIBOR
Basis spread over LIBOR	37	36
Principal amount	$ 425	$ 452
Weighted average life of other debt	5 years 9 months 18 days
TBA securities Fifteen Year and Thirty Year Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Fair Value, Net	$ 70	(147)
TBA and Forward Settling Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Forward Settlement Value	14,377	11,312
Derivative, Fair Value, Net	70	(147)
Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	$ 39,375	$ 37,686

Repurchase Agreements And Oth37

Repurchase Agreements And Other Debt (Repurchase Arrangements And Weighted Average Interest Rates Classified By Original Maturities) (Details) $ in Millions	Mar. 31, 2017USD ($)days	Dec. 31, 2016USD ($)days
Repurchase Agreements | $	$ 39,375	$ 37,858
Weighted Average Days to Maturity | days	176	186
30 Days or Less [Member]
Repurchase Agreements | $	$ 18,574	$ 17,481
Weighted Average Interest Rate	0.94%	0.90%
Weighted Average Days to Maturity | days	13	11
1 to 3 Months
Repurchase Agreements | $	$ 8,728	$ 10,011
Weighted Average Interest Rate	1.02%	0.93%
Weighted Average Days to Maturity | days	55	55
3 to 6 Months
Repurchase Agreements | $	$ 1,831	$ 2,030
Weighted Average Interest Rate	0.97%	1.02%
Weighted Average Days to Maturity | days	121	136
6 to 9 Months
Repurchase Agreements | $	$ 3,668	$ 1,270
Weighted Average Interest Rate	1.10%	0.98%
Weighted Average Days to Maturity | days	224	214
9 to 12 Months
Repurchase Agreements | $	$ 1,361	$ 1,566
Weighted Average Interest Rate	1.11%	1.08%
Weighted Average Days to Maturity | days	284	299
12 to 24 Months
Repurchase Agreements | $	$ 1,588	$ 1,203
Weighted Average Interest Rate	1.43%	1.28%
Weighted Average Days to Maturity | days	524	538
24 to 36 Months
Repurchase Agreements | $	$ 2,300	$ 1,300
Weighted Average Interest Rate	1.50%	1.36%
Weighted Average Days to Maturity | days	961	865
36 to 48 months
Repurchase Agreements | $	$ 1,325	$ 2,200
Weighted Average Interest Rate	1.49%	1.32%
Weighted Average Days to Maturity | days	1,302	1,168
48 to 60 Months
Repurchase Agreements | $	$ 0	$ 625
Weighted Average Interest Rate	0.00%	1.38%
Weighted Average Days to Maturity | days	0	1,506
2 Days to 1 Month [Member]
Weighted Average Interest Rate	0.00%	(0.30%)
Weighted Average Days to Maturity | days	0	17
Repurchase Agreements [Member]
Weighted Average Interest Rate	1.05%	0.98%
Agency Securities [Member]
Repurchase Agreements | $	$ 39,375	$ 37,686
Weighted Average Days to Maturity | days	176	187
Agency Securities [Member] | Repurchase Agreements [Member]
Weighted Average Interest Rate	1.05%	0.98%
US Treasury Securities [Member] | 2 Days to 1 Month [Member]
Repurchase Agreements | $	$ 0	$ 172

Repurchase Agreements And Oth38

Repurchase Agreements And Other Debt Federal Home Loan Bank Advances and Weighted Average Interest Rates (Details) $ in Millions	Dec. 31, 2016USD ($)
Short-term Debt [Line Items]
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.73%
Advances from Federal Home Loan Banks	$ 3,037

Derivative and Other Hedging 39

Derivative and Other Hedging Instruments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Forward Contracts [Member] | Interest Rate Swap [Member]
Average Maturity (Years)	12 years		10 years 8 months 12 days
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (11)	$ (7)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	1,000	0
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	0	(400)
TBA and Forward Settling Agency Securities [Member]
Notional Amount	14,170	5,813	$ 10,916	$ 7,295
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	39	216
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	36,096	17,959
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		(19,441)
US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(12)	(77)
Gain Loss on Other Debt	(1)	(5)
Unrealized gain on derivative instruments, net	0	19
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(39)	(951)
Discontinuation of Election to Account for Interest Rate Swaps as Designated Cash Flow Hedges [Member]
Net Unrealized Gain (Loss) on Swaps	0	20	0	39
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Notional Amount	2,200
Short [Member] | US Treasury Securities [Member]
Notional Amount	9,169	3,135	8,061	1,714
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(78)	(83)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	2,558	1,980
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(1,450)	(559)
Long [Member] | US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	1	5
Trading Securities Added During the Period	303	180
Notional Amount Of Trading Securities Settlement Expiration During The Period	(492)	(205)
Trading Securities		0	$ 189	$ 25
Long [Member]
Trading Securities	$ 0
Other Derivatives [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		$ 12

Derivative and Other Hedging 40

Derivative and Other Hedging Instruments (Fair Value Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative asset, fair value	$ 205		$ 355
Derivative liability, fair value	(69)		(256)
Derivative assets, at fair value	205		355
Derivative Liability	(69)		(256)
U.S. Treasury securities	0		182
U.S. Treasury Securities - short	(8,792)		(7,636)
Total - (short)/long, net	(8,792)		(7,454)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(39)	$ (951)
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	14,170	5,813	10,916	$ 7,295
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	36,096	17,959
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		(19,441)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	39	216
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	35,775		37,175
Derivative liability, fair value	(43)		(105)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	1,300	1,000
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(2,700)	(3,350)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	22	(1,005)
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	92		321
Interest Rate Swaption [Member]
Derivative [Line Items]
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	1,000	0
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	0	(400)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(11)	(7)
Interest Rate Swaption [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	22		22
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative liability, fair value	(21)		(151)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(32,842)
US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(12)	(77)
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	0		8
Derivative Liability	(5)		0
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	91		4
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	35,775
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	2,200
Short [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	9,169	3,135	8,061	1,714
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	2,558	1,980
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(1,450)	(559)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(78)	(83)
Long [Member]
Derivative [Line Items]
Trading Securities	0
Long [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	1	5
Trading Securities		0	$ 189	$ 25
Trading Securities Added During the Period	303	180
Notional Amount Of Trading Securities Settlement Expiration During The Period	$ (492)	$ (205)

Derivative and Other Hedging 41

Derivative and Other Hedging Instruments (Summary Of Outstanding Interest Rate Swaps) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Gain Loss on Other Debt	$ (1)	$ (5)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (39)	(951)
Forward Contracts [Member] | Interest Rate Swap [Member]
Average Maturity (Years)	12 years		10 years 8 months 12 days
Derivative, Notional Amount	$ 300		$ 600
Weighted Average Forward Start Date	2 years		1 year 2 months 12 days
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 22	(1,005)
Notional Amount	$ 35,775		$ 37,175
Average Fixed Pay Rate	1.52%		1.48%
Average Receive Rate	1.06%		0.92%
Average Maturity (Years)	3 years 10 months 24 days		3 years 10 months 24 days
Greater Than One Year and Less Than or Equal to Three Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 19,825		$ 19,775
Average Fixed Pay Rate	1.21%		1.16%
Average Receive Rate	1.06%		0.92%
Average Maturity (Years)	1 year 7 months 6 days		1 year 6 months
Greater Than Three Years and Less Than or Equal to Five Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 6,250		$ 7,450
Average Fixed Pay Rate	1.72%		1.62%
Average Receive Rate	1.06%		0.91%
Average Maturity (Years)	4 years 1 month 6 days		4 years
Greater Than Five Years and Less than or Equal to Seven Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 3,975		$ 4,725
Average Fixed Pay Rate	1.82%		1.89%
Average Receive Rate	1.04%		0.91%
Average Maturity (Years)	5 years 7 months 6 days		5 years 10 months 24 days
Greater Than Seven Years and Less than or Equal to Ten Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 3,625		$ 3,325
Average Fixed Pay Rate	1.94%		1.90%
Average Receive Rate	1.05%		0.91%
Average Maturity (Years)	9 years 1 month 6 days		9 years 2 months 12 days
Greater Than Ten Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 2,100		$ 1,900
Average Fixed Pay Rate	2.58%		2.64%
Average Receive Rate	1.05%		0.91%
Average Maturity (Years)	13 years 6 months		13 years 9 months 18 days
Other Derivatives [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		$ 12

Derivative and Other Hedging 42

Derivative and Other Hedging Instruments (Remaining Interest Rate Swap Term) (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017USD ($)month	Mar. 31, 2016USD ($)	Dec. 31, 2016USD ($)month
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (39)	$ (951)
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(11)	(7)
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	22	(1,005)
Derivative Liability, Notional Amount	$ 35,775		$ 37,175
Average Fixed Pay Rate	1.52%		1.48%
Average Maturity (Years)	3 years 10 months 24 days		3 years 10 months 24 days
Less Than or Equal to One Year [Member] | Interest Rate Swaption [Member]
Cost	$ 64		$ 52
Fair Value	$ 22		$ 22
Average Months to Expiration | month	8		6
Derivative Liability, Notional Amount	$ 2,200		$ 1,200
Average Fixed Pay Rate	3.09%		3.06%
Average Maturity (Years)	8 years 10 months 24 days		8 years 3 months 18 days
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	$ 19,825		$ 19,775
Average Fixed Pay Rate	1.21%		1.16%
Average Maturity (Years)	1 year 7 months 6 days		1 year 6 months
Other Derivatives [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		$ 12
Interest Rate Swaps Excluding Forward Starting [Member] | Interest Rate Swap [Member]
Average Fixed Pay Rate	1.50%		1.46%

Derivative and Other Hedging 43

Derivative and Other Hedging Instruments (US Treasury Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
U.S. Treasury securities, net	$ (8,792)	$ (7,454)
7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(4,135)	(3,056)
At Par Value [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(9,169)	(7,872)
US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	(5)	8
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(14,170)	(10,916)
Derivative, Forward Settlement Value	(14,377)	(11,312)
Derivative Asset, Fair Value, Gross Asset	(14,447)	(11,165)
Derivative, Fair Value, Net	70	(147)
5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	0	(400)
10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(5,034)	(4,416)
10 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	(4)	5
5 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	(1)	3
Short [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,810)	(1,810)
Derivative, Forward Settlement Value	(2,199)	(2,209)
Derivative Asset, Fair Value, Gross Asset	(2,204)	(2,201)
Short [Member] | 10 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,080)	(1,080)
Derivative, Forward Settlement Value	(1,341)	(1,347)
Derivative Asset, Fair Value, Gross Asset	(1,345)	(1,342)
Short [Member] | 5 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(730)	(730)
Derivative, Forward Settlement Value	(858)	(862)
Derivative Asset, Fair Value, Gross Asset	(859)	(859)
Fair Value Hedging [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(8,792)	(7,454)
Fair Value Hedging [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(4,036)	(2,930)
Fair Value Hedging [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	0	(392)
Fair Value Hedging [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(4,756)	(4,132)
At Cost Basis [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(8,935)	(7,681)
At Cost Basis [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(4,106)	(3,041)
At Cost Basis [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	0	(404)
At Cost Basis [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	$ (4,829)	$ (4,236)

Derivative and Other Hedging 44

Derivative and Other Hedging Instruments (TBA Securities by Coupon and Issuer) (Details) - TBA and Forward Settling Agency Securities [Member] - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative, Notional Amount	$ (14,170)	$ (10,916)
Cost Basis	(14,377)	(11,312)
Net long TBA position, at fair value	(14,447)	(11,165)
TBA, net carrying value	70	(147)
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Derivative [Line Items]
Derivative, Notional Amount	0	0
Cost Basis	0	(1)
Net long TBA position, at fair value	0	0
TBA, net carrying value	0	(1)
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,641)	(1,035)
Cost Basis	(1,657)	(1,060)
Net long TBA position, at fair value	(1,660)	(1,047)
TBA, net carrying value	3	(13)
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Derivative [Line Items]
Derivative, Notional Amount	(12,529)	(9,881)
Cost Basis	(12,720)	(10,251)
Net long TBA position, at fair value	(12,787)	(10,118)
TBA, net carrying value	67	(133)
30 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	(12,019)	(8,756)
Cost Basis	(12,227)	(9,124)
Net long TBA position, at fair value	(12,292)	(8,993)
TBA, net carrying value	65	(131)
30 Year Maturity [Member] | 3.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(3,686)	(3,027)
Cost Basis	(3,642)	(3,114)
Net long TBA position, at fair value	(3,648)	(3,007)
TBA, net carrying value	6	(107)
30 Year Maturity [Member] | 3.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(3,295)	(1,209)
Cost Basis	(3,347)	(1,251)
Net long TBA position, at fair value	(3,369)	(1,236)
TBA, net carrying value	22	(15)
30 Year Maturity [Member] | 4.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(5,070)	(4,530)
Cost Basis	(5,273)	(4,769)
Net long TBA position, at fair value	(5,310)	(4,760)
TBA, net carrying value	37	(9)
30 Year Maturity [Member] | 4.5% Coupon [Member]
Derivative [Line Items]
TBA, net carrying value	0	0
30 Year Maturity [Member] | Short [Member] | 4.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(32)	(10)
Cost Basis	(35)	(10)
Net long TBA position, at fair value	(35)	(10)
15 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	(2,151)	(2,160)
Cost Basis	(2,150)	(2,188)
Net long TBA position, at fair value	(2,155)	(2,172)
TBA, net carrying value	5	(16)
15 Year Maturity [Member] | 2.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,980)	(1,853)
Cost Basis	(1,973)	(1,870)
Net long TBA position, at fair value	(1,978)	(1,856)
TBA, net carrying value	5	(14)
15 Year Maturity [Member] | 3.0% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(32)	(292)
Cost Basis	(33)	(302)
Net long TBA position, at fair value	(33)	(300)
TBA, net carrying value	0	(2)
15 Year Maturity [Member] | 3.5% Coupon [Member]
Derivative [Line Items]
Derivative, Notional Amount	(139)	(15)
Cost Basis	(144)	(16)
Net long TBA position, at fair value	(144)	(16)
TBA, net carrying value	$ 0	$ 0

Derivative and Other Hedging 45

Derivative and Other Hedging Instruments (Effect Of Derivative Instruments Not Designated As Hedges On Comprehensive Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	$ (39)	$ (951)
Gain Loss on Other Debt	(1)	(5)
Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Additions	(1,000)	0
Settlement, Expirations or Exercise	0	400
Amount Gain/(Loss) Recognized in Income on Derivatives	(11)	(7)
TBA and Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(10,916)	(7,295)
Additions	(36,096)	(17,959)
Settlement, Expirations or Exercise		19,441
Notional Amount	(14,170)	(5,813)
Amount Gain/(Loss) Recognized in Income on Derivatives	39	216
Derivative, Notional Amount	14,170		$ 10,916
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Settlement, Expirations or Exercise	32,842
Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(37,175)
Additions	(1,300)	(1,000)
Settlement, Expirations or Exercise	2,700	3,350
Notional Amount	(35,775)
Amount Gain/(Loss) Recognized in Income on Derivatives	22	(1,005)
US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	(12)	(77)
Other derivative instruments [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives		12
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(2,200)
Derivative, Notional Amount		1,750	1,200	$ 2,150
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(35,775)
Derivative, Notional Amount		38,175	37,175	40,525
Short [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(8,061)	(1,714)
Additions	(2,558)	(1,980)
Settlement, Expirations or Exercise	1,450	559
Notional Amount	(9,169)	(3,135)
Amount Gain/(Loss) Recognized in Income on Derivatives	(78)	(83)
Derivative, Notional Amount	1,810		1,810
Long [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Trading Securities	0
Long [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	1	5
Trading Securities		0	$ 189	$ 25
Trading Securities Added During the Period	303	180
Notional Amount Of Trading Securities Settlement Expiration During The Period	(492)	(205)
Future [Member] | Short [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(1,810)	(1,860)
Additions	(1,810)	(1,860)
Settlement, Expirations or Exercise	1,810	1,860
Notional Amount	$ (1,810)	$ (1,860)

Pledged Assets (Narrative) (Det

Pledged Assets (Narrative) (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Pledged Assets [Abstract]
Federal Home Loan Bank Stock		$ 126,000,000
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	Mar. 31, 2017USD ($)daysmonth	Dec. 31, 2016USD ($)daysmonth
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Securities Sold under Agreements to Repurchase	$ 39,375	$ 37,858
Weighted Average Days to Maturity | days	176	186
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	$ 4,775	$ 4,875
Risk Of Repurchase Agreement To Stockholders Equity	5.20%	5.50%
Counterparty Exposure, Net	$ 381	$ 405
Repurchase Agreements Weighted Average Months To Maturity | month	31.8	34.1

Pledged Assets (Assets Pledged

Pledged Assets (Assets Pledged as Collateral) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Offsetting Assets and Liabilities [Line Items]
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repurchase Agreements	$ 200	$ 181
Federal Home Loan Bank Stock		126
Available-for-sale Securities Pledged as Collateral	41,587	43,943
Accrued interest on pledged securities	122	128
Restricted cash and cash equivalents	219	74
Total Fair Value of Securities Pledged and Accrued Interest	43,442
Total Fair Value Of Agency Securities Pledged And Accrued Interest		45,428
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	41,463	43,005
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	259	275
Accrued interest on pledged securities		1
Restricted cash and cash equivalents	150	14
Total Fair Value of Securities Pledged and Accrued Interest	410
Total Fair Value Of Agency Securities Pledged And Accrued Interest		290
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Accrued interest on pledged securities	117	122
Total Fair Value of Securities Pledged and Accrued Interest	41,599
Total Fair Value Of Agency Securities Pledged And Accrued Interest		43,450
Variable Interest Entity, Primary Beneficiary [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	777	818
Accrued interest on pledged securities	2	3
Total Fair Value of Securities Pledged and Accrued Interest	779
Total Fair Value Of Agency Securities Pledged And Accrued Interest		821
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	602	865
Accrued interest on pledged securities	2	2
Total Fair Value of Securities Pledged and Accrued Interest	654
Total Fair Value Of Agency Securities Pledged And Accrued Interest		867
Includes Sold But Not Yet Settled Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	43,101	44,963
AAA Non-Agency Mortgage-Backed Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	90
AAA Non-Agency Mortgage-Backed Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	90
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	173
US Treasury Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	173
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	19	60
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash and cash equivalents	50	0
Excluding Cash Received [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash and cash equivalents	$ 219	$ 74

Pledged Assets (Securities Pled

Pledged Assets (Securities Pledged as Collateral) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Offsetting Assets and Liabilities [Line Items]
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repo	$ 200	$ 181
Security Owned and Pledged as Collateral, Fair Value	41,463	43,269
Agency Securities Pledged As Collateral Amortized Cost	41,794	43,644
Agency Securities Pledged As Collateral Accrued Interest	117	122
Maturity Less than 30 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	19,299	19,681
Agency Securities Pledged As Collateral Amortized Cost	19,456	19,863
Agency Securities Pledged As Collateral Accrued Interest	55	56
Maturity 31 To 59 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	5,377	8,103
Agency Securities Pledged As Collateral Amortized Cost	5,415	8,158
Agency Securities Pledged As Collateral Accrued Interest	16	23
Maturity 60 To 90 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	3,448	4,034
Agency Securities Pledged As Collateral Amortized Cost	3,475	4,070
Agency Securities Pledged As Collateral Accrued Interest	10	11
Maturity over 90 days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	13,339	11,278
Agency Securities Pledged As Collateral Amortized Cost	13,448	11,380
Agency Securities Pledged As Collateral Accrued Interest	36	32
2 Days to 1 Month [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	0	173
Agency Securities Pledged As Collateral Amortized Cost	0	173
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	41,463	43,096
Agency Securities Pledged As Collateral Amortized Cost	41,794	43,471
Agency Securities Pledged As Collateral Accrued Interest	$ 117	$ 122

Pledged Assets (Assets Pledge50

Pledged Assets (Assets Pledged from Counterparties) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Offsetting Assets and Liabilities [Line Items]
Federal Home Loan Bank Stock		$ 126
Available-for-sale Securities Pledged as Collateral	$ 41,587	43,943
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	8,792	7,636
Restricted Cash and Cash Equivalents	219	74
Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	14
Restricted Cash and Cash Equivalents	10	107
Restricted Cash and Securities Pledged	8,867	7,757
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	0	14
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	0	14
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	28	107
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	173
US Treasury Securities [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	8,857	7,636
Reverse Repurchase Agreements [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	8,839	7,636
Reverse Repurchase Agreements [Member] | US Treasury Securities [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	8,839	7,636
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	259	275
Restricted Cash and Cash Equivalents	150	14
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	18	0
Derivative [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	$ 10	$ 107

Pledged Assets (Offsetting Asse

Pledged Assets (Offsetting Assets and Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Offsetting Assets and Liabilities [Line Items]
Collateral Received	$ (1,667)
Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	9,113	$ 8,062
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	9,113	8,062
Financial Instruments	(7,321)	(7,047)
Collateral Received		(802)
Net Amount	125	213
Assets [Member] | ERROR in label resolution.
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	114	342
Net Amounts of Assets Presented in the Consolidated Balance Sheets	114	342
Financial Instruments	(31)	(80)
Collateral Received	(28)	(49)
Net Amount	55	213
Assets [Member] | TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	91	4
Net Amounts of Assets Presented in the Consolidated Balance Sheets	91	4
Financial Instruments	(21)	(4)
Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	39,439	41,151
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	39,439	41,151
Financial Instruments	(7,321)	(7,047)
Collateral Received	(32,118)	(34,104)
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	43	105
Net Amounts of Assets Presented in the Consolidated Balance Sheets	43	105
Financial Instruments	(31)	(80)
Collateral Received	(12)	(25)
Net Amount	0	0
Liability [Member] | TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	21	151
Net Amounts of Assets Presented in the Consolidated Balance Sheets	21	151
Financial Instruments	(21)	(4)
Collateral Received	0	(147)
Net Amount	0	0
Reverse Repurchase Agreements [Member] | Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	8,908	7,716
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	8,908	7,716
Financial Instruments	(7,269)	(6,963)
Collateral Received	(1,639)	(753)
Repurchase Agreements [Member] | Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	39,375	40,895
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	39,375	40,895
Financial Instruments	(7,269)	(6,963)
Collateral Received	$ (32,106)	$ (33,932)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
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	$ 0	$ 8
Derivative Liability	5	0
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	22
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	92	321
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	43	105
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	$ 91	4
Transfers between hierarchy levels	0
Agency securities	$ 43,856	45,393
Agency securities transferred to consolidated VIEs	777	818
Non-Agency Securities, at Fair Value	31	124
Financial Instruments, Owned, Other, at Fair Value	383	164
U.S. Treasury securities	0	182
TBA securities	205	355
Derivative Liability	69	256
Debt of consolidated variable interest entities, at fair value	434	460
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	8,792	7,636
Interest rate swaps	205	355
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	0	190
Total liabilities	8,797	7,636
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	45,252	46,846
Total liabilities	498	716
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	$ 21	$ 151

Net Income (Loss) Per Common 53

Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average Number of Shares Outstanding, Basic	331	334.4
Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units	$ 0.1	$ 0
Weighted Average Number of Shares Outstanding, Diluted	331.1	334.4
Net Income (Loss) Available to Common Stockholders, Basic	$ 69	$ (779)
Earnings Per Share, Basic and Diluted	$ 0.21	$ (2.33)

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	Mar. 31, 2016	Dec. 31, 2012	Mar. 31, 2017	Dec. 31, 2016	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
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
Series A Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Dividend Rate, Percentage			8.00%
Preferred Stock, Liquidation Preference Per Share							$ 25
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
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	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Oct. 31, 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)
Average repurchase price (in dollars per share)		$ 17.89
Repurchase of common stock, value		$ 116
Payments for Repurchase of Common Stock	0	$ 116
Remaining amount authorized for repurchase	$ 1,000
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of common stock shares		(6.5)
Repurchase of common stock, value		$ 0

Stockholders' Equity (Accumulat

Stockholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Accumulated OCI Balance	$ (351)	$ 718	$ (397)	$ (66)
OCI before reclassifications	46	765
Amounts reclassified from accumulated OCI	0	19
Total Accumulated OCI Balance	84	21
Agency Securities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning OCI Balance	(397)	(27)
OCI before reclassifications	(38)	763
Amounts reclassified from accumulated OCI	84	2
Ending OCI Balance	(351)	738
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	(20)	$ 0	$ (39)
Interest Rate Swap [Member] | Agency Securities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
OCI before reclassifications	$ (38)	$ 763

Stockholders' Equity (Follow-On

Stockholders' Equity (Follow-On Equity Offerings) (Details) - shares shares in Millions	Mar. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares, Issued	331	331

Stockholders' Equity (At-the-Ma

Stockholders' Equity (At-the-Market Offering Program) (Details) - USD ($) shares in Millions, $ in Millions	Mar. 31, 2017	Feb. 28, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares, Issued	331		331
Common Stock, Capital Shares Reserved for Future Issuance		$ 750

Subsequent Event (Details)

Subsequent Event (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	May 05, 2017	Apr. 13, 2017	Mar. 31, 2017	Mar. 31, 2016
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared			$ 0.54	$ 0.60
Subsequent Event [Member]
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared		$ 0.18
Stock Issued During Period, Shares, New Issues	24.5
Stock Issued During Period, Value, New Issues	$ 503
Sale of Stock, Price Per Share	$ 20.53
Common Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Stock Issued During Period, Shares, New Issues	3.7