AGNC Investment (AGNC) 10-Q 6 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 31, 2015
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Entity Registrant Name	American Capital Agency 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		346,450,083
Trading Symbol	AGNC

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Assets:
Agency securities, at fair value (including pledged securities of $47,319 and $51,629, respectively)	$ 53,729	$ 55,482
Agency securities transferred to consolidated variable interest entities, at fair value (pledged securities)	1,088	1,266
U.S. Treasury securities, at fair value (including pledged securities of $767 and $2,375, respectively)	787	2,427
REIT equity securities, at fair value	34	68
Cash and cash equivalents	1,505	1,720
Restricted cash	1,413	713
Derivative assets, at fair value	143	408
Receivable for securities sold (including pledged securities of $147 and $79, respectively)	147	239
Receivable under reverse repurchase agreements	1,463	5,218
Other assets	300	225
Total assets	60,609	67,766
Liabilities:
Repurchase Agreements	41,014	50,296
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,502	0
Debt of consolidated variable interest entities, at fair value	626	761
Payable for agency securities purchased	4,178	843
Derivative liabilities, at fair value	1,536	890
Dividend payable	76	85
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	1,309	5,363
Accounts payable and other accrued liabilities	52	100
Total liabilities	52,293	58,338
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; 346.5 and 352.8 shares issued and outstanding, respectively	3	4
Additional paid-in capital	10,209	10,332
Retained deficit	(2,727)	(1,674)
Accumulated other comprehensive income	495	430
Total stockholders' equity	8,316	9,428
Total liabilities and stockholders' equity	$ 60,609	$ 67,766

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Millions, $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Available-for-sale Securities Pledged as Collateral	$ 47,319	$ 51,629
Trading Securities Pledged as Collateral	767	2,375
Assets Pledged included in Receivable for Securities Sold	$ 147	$ 79
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	346.5	352.8
Common Stock, Shares, Outstanding	346.5	352.8

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest income:
Interest income	$ 295	$ 357	$ 1,092	$ 1,141
Interest expense	77	88	244	291
Net interest income	218	269	848	850
Other income, net:
Gain (loss) on sale of agency securities, net	(39)	14	(25)	17
Loss on derivative instruments and other securities, net	(778)	(51)	(1,090)	(672)
Total other income, net	(817)	(37)	(1,115)	(655)
Expenses:
Management fees	29	30	88	89
General and administrative expenses	5	5	18	17
Total expenses	34	35	106	106
Net income (loss)	(633)	197	(373)	89
Dividend on preferred stock	7	7	21	16
Net income (loss) available (attributable) to common stockholders	(640)	190	(394)	73
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(467)	253	14	(1,059)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, De-Designated Interest Rate Swaps			(79)	(121)
Unrealized gain on derivative instruments, net	24	38	79	121
Other comprehensive income (loss)	491	(215)	65	1,180
Comprehensive income (loss)	(142)	(18)	(308)	1,269
Comprehensive income (loss) available (attributable) to common stockholders	$ (149)	$ (25)	$ (329)	$ 1,253
Weighted average number of common shares outstanding-basic and diluted (shares)	347.8	352.8	350.9	353.5
Net loss per common share - basic and diluted (dollars per share)	$ (1.84)	$ 0.54	$ (1.12)	$ 0.21
Dividends declared per common share	$ 0.6	$ 0.65	$ 1.88000000	$ 1.95000000

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance, value at Dec. 31, 2013	$ 8,697	$ 167	$ 4	$ 10,406	$ (497)	$ (1,383)
Balance, Preferred Stock, shares at Dec. 31, 2013		6.9
Balance, Common Stock, shares at Dec. 31, 2013			356.2
Net income (loss)	89				89
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	1,059					1,059
Amounts reclassified from accumulated OCI	121					121
Issuance of preferred stock	169	$ 169
Repurchase of common stock	(74)			(74)
Payments for Repurchase of Common Stock	74
Repurchase of common stock shares			(3.4)
Preferred dividends declared	(16)				(16)
Common dividends declared	(688)				(688)
Balance, value at Sep. 30, 2014	9,357	$ 336	$ 4	10,332	(1,112)	(203)
Balance, Preferred Stock, shares at Sep. 30, 2014		6.9
Balance, Common Stock, shares at Sep. 30, 2014			352.8
Balance, value at Dec. 31, 2014	$ 9,428	$ 336	$ 4	10,332	(1,674)	430
Balance, Preferred Stock, shares at Dec. 31, 2014	6.9	6.9
Balance, Common Stock, shares at Dec. 31, 2014	352.8		352.8
Net income (loss)	$ (373)				(373)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(14)					(14)
Amounts reclassified from accumulated OCI	79					79
Issuance of preferred stock	0
Repurchase of common stock	(124)		$ (1)	(123)
Payments for Repurchase of Common Stock	124
Repurchase of common stock shares			(6.3)
Preferred dividends declared	(21)				(21)
Common dividends declared	(659)				(659)
Balance, value at Sep. 30, 2015	$ 8,316	$ 336	$ 3	$ 10,209	$ (2,727)	$ 495
Balance, Preferred Stock, shares at Sep. 30, 2015	6.9	6.9
Balance, Common Stock, shares at Sep. 30, 2015	346.5		346.5

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating activities:
Net income (loss)	$ (373)	$ 89
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of agency securities premiums and discounts, net	330	351
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, De-Designated Interest Rate Swaps	79	121
(Gain) loss on sale of agency securities, net	25	(17)
Loss on derivative instruments and other securities, net	1,090	672
(Increase) decrease in other assets	(73)	71
Increase (decrease) in accounts payable and other accrued liabilities	(8)	7
Net cash provided by operating activities	1,070	1,294
Investing activities:
Purchases of agency securities	(23,792)	(15,342)
Proceeds from sale of agency securities	22,615	25,404
Principal collections on agency securities	6,177	5,678
Purchases of U.S. Treasury securities	(46,774)	(28,889)
Proceeds from sale of U.S. Treasury securities	44,237	34,203
Net proceeds from (payments on) reverse repurchase agreements	3,755	(3,377)
Net proceeds from (payments on) other derivative instruments	(85)	282
Purchases of REIT equity securities	(11)	(204)
Proceeds from sale of REIT equity securities	35	386
Increase in restricted cash	(700)	(693)
Other investing cash flows, net	(28)	(244)
Net cash provided by investing activities	5,429	17,204
Financing activities:
Proceeds from repurchase arrangements, net	317,718	216,945
Repayments on repurchase agreements	(327,000)	(235,151)
Proceeds from Federal Home Loan Bank Advances	5,437	0
Repayments of Federal Home Loan Bank Borrowings	(1,935)	0
Repayments on debt of consolidated variable interest entities	(121)	(119)
Net proceeds from preferred stock issuance	0	169
Payments for common stock repurchases	(124)	(74)
Cash dividends paid	(689)	(703)
Net cash used in financing activities	(6,714)	(18,933)
Net change in cash and cash equivalents	(215)	(435)
Cash and cash equivalents at beginning of period	1,720	2,143
Cash and cash equivalents at end of period	$ 1,505	$ 1,708

Unaudited Interim Consolidated

Unaudited Interim Consolidated Financial Statements	9 Months Ended
	Sep. 30, 2015
Quarterly Financial Information Disclosure [Abstract]
Unaudited Interim Consolidated Financial Statements	Unaudited Interim Consolidated Financial Statements The unaudited interim consolidated financial statements of American Capital Agency 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 our wholly-owned subsidiaries, American Capital Agency TRS, LLC and Old Georgetown Insurance Co., LLC, and variable interest entities for which the Company is 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	9 Months Ended
	Sep. 30, 2015
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 are externally managed by American Capital AGNC Management, LLC (our "Manager"), an affiliate of American Capital, Ltd. ("American Capital"). 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 all of our annual taxable net income to our stockholders. 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 on a leveraged basis in agency mortgage-backed securities ("agency MBS"). These investments consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") for which the principal and interest payments are guaranteed by a 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"). We may also invest in other assets reasonably related to agency securities and up to 10% of our assets in AAA non-agency and commercial mortgage-backed securities (collectively referred to as "AAA non-agency securities"). Our principal objective is to generate attractive risk-adjusted returns for distribution to our stockholders through regular monthly dividends from the combination of our net interest income and net realized gains and losses on our investments and hedging activities while preserving our net asset value (also referred to as "net book value," "NAV" and "stockholders' equity"). We fund our investments primarily through short-term borrowings structured as repurchase agreements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Investment Securities ASC Topic 320, Investments—Debt and Equity Securities ("ASC 320"), 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. Securities classified as trading and available-for-sale are reported at fair value, while securities classified as held-to-maturity are reported at amortized cost. We may sell any of our securities as part of our overall management of our investment portfolio. Accordingly, we typically designate our agency and AAA non-agency securities as available-for-sale. All securities classified as available-for-sale are reported at fair value, with unrealized gains and losses reported in accumulated other comprehensive income (loss) ("OCI"), a separate component of stockholders' equity. Upon the sale of a security, 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. Interest-only securities and inverse interest-only securities (collectively referred to as "interest-only securities") represent our right to receive a specified proportion of the contractual interest cash flows of specific agency CMO securities. Principal-only securities represent our right to receive the contractual principal cash flows of specific agency CMO securities. Interest and principal-only securities are measured at fair value through earnings in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Our investments in interest and principal-only securities are included in agency securities, at fair value on the accompanying consolidated balance sheets. REIT equity securities represent investments in the common stock of other publicly traded mortgage REITs that invest predominantly in agency MBS. We designate our investments in REIT equity securities as trading securities and report them at fair value on the accompanying consolidated balance sheets. We estimate the fair value of our agency and AAA non-agency securities based on valuations obtained from third-party pricing services and non-binding dealer quotes derived from common market pricing methods using observable (or "Level 2") inputs. Such methods incorporate, but are not limited to, reported trades and executable bid and asked prices for similar securities, benchmark interest rate curves, such as the spread to the U.S. Treasury rate and interest rate swap curves, convexity, duration and the underlying characteristics of the particular security, including coupon, periodic and life caps, rate reset period, issuer, additional credit support and expected life of the security. We estimate the fair value of our REIT equity securities based on a market approach using quoted market prices (or "Level 1" inputs). Refer to Note 8 for further discussion of fair value measurements. We evaluate our investment securities 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. The liquidity of the agency and AAA non-agency securities market allows us to obtain competitive bids and execute on a sale transaction typically within one to two days of making the decision to sell a security and, therefore, we generally do not make decisions to sell specific securities until shortly prior to initiating a sell order. In some instances, we may sell specific agency securities by delivering such securities into existing short to-be-announced ("TBA") contracts. TBA market conventions require the identification of the specific agency securities to be delivered no later than 48 hours prior to settlement. If we settle a short TBA contract through the delivery of securities, we will generally identify the specific securities to be delivered within one to two days of the 48-hour deadline. 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 investment securities 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 ("ASC 310-20"). We estimate long-term prepayment speeds of our agency and AAA non-agency securities using a third-party service and market data. The third-party service estimates prepayment speeds using models that incorporate the forward yield curve, current mortgage rates and mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, volatility and other factors. We review the prepayment speeds estimated by the third-party service and compare the results to market consensus prepayment speeds, if available. We also consider historical prepayment speeds and current market conditions to validate the reasonableness of the prepayment speeds estimated by the third-party service. As market conditions may change rapidly, we may make adjustments for different securities based on our Manager's judgment. Various market participants could use materially different assumptions. 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. Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate risk, prepayment risk and extension 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 forward contracts for the purchase or sale of agency MBS securities in the "to-be-announced" market ("TBA securities"), U.S. Treasury securities and U.S. Treasury futures contracts. We may also purchase or write put or call options on TBA securities and invest in mortgage and other types of derivative instruments, such as interest and principal-only securities. We may 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). Pursuant to 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 the balance sheet and to measure those instruments at fair value. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with the counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. Derivative instruments in a gain position are reported as derivative assets at fair value and derivative instruments in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Changes in fair value of derivative instruments and periodic settlements related to our derivative instruments are recorded in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized in the event that the counterparties to these instruments fail to perform their obligations under the contracts. We attempt to minimize this risk by limiting our counterparties to major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Discontinuation of hedge accounting for interest rate swap agreements Prior to September 30, 2011, we entered into interest rate swap agreements typically with the intention of qualifying for hedge accounting under ASC 815. However, as of September 30, 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 is being reclassified from accumulated OCI into interest expense on a straight-line basis over the remaining term of each interest rate swap. Interest rate swap agreements We use interest rate swaps to hedge the variable cash flows associated with borrowings made under our repurchase agreements and Federal Home Loan Bank advance facility. 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 funding agreements and cash flows on such liabilities. Our swap agreements are privately negotiated in the over−the−counter ("OTC") market, with swap agreements entered into subsequent to May 2013 subject to central clearing through a registered commodities exchange ("centrally cleared swaps"). We estimate the fair value of our centrally cleared interest rate swaps using the daily settlement price determined by the respective exchange. Centrally cleared swaps are valued by the exchange using a pricing model that references the underlying rates including the overnight index swap rate and LIBOR forward rate to produce the daily settlement price. We estimate the fair value of our "non-centrally cleared" interest rate swaps based on valuations obtained from third-party pricing services and the swap counterparty (collectively, “third-party valuations”). The third-party valuations are model-driven using observable inputs consisting of LIBOR and the forward yield curve. We also consider the creditworthiness of both us and our counterparties and the impact of netting and credit enhancement provisions contained in each derivative agreement, such as collateral postings. All of our "non-centrally cleared" interest rate swaps are subject to bilateral collateral arrangements. Consequently, no credit valuation adjustment was made in determining the fair value of such instruments. 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 our interest rate swaption agreements based on model-driven valuations obtained from third-party pricing services and the swaption counterparty using observable inputs, taking into account 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 MBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific agency MBS 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 we may utilize TBA dollar roll transactions to finance agency MBS 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 MBS securities. U.S. Treasury securities We purchase or 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 the balance sheet 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 Securities

Investment Securities	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Investment Securities	3 years and ≤ 5 years 19,210 18,870 3.28% 2.40% 22,153 21,820 3.26% 2.40% > 5 years and ≤10 years 34,856 34,648 3.65% 2.91% 33,271 33,055 3.73% 2.92% > 10 years 66 65 3.78% 3.37% 633 621 3.28% 3.15% Total $ 54,454 $ 53,899 3.52% 2.72% $ 56,346 $ 55,776 3.54% 2.72% _______________________ 1. Excludes interest and principal-only strips. The weighted average life of our interest-only strips was 5.9 and 6.0 years as of September 30, 2015 and December 31, 2014 , respectively. The weighted average life of our principal-only strips was 7.8 and 8.1 years as of September 30, 2015 and December 31, 2014 , respectively. Securities classified as available-for-sale are reported at fair value, with unrealized gains and losses excluded from earnings and reported in accumulated OCI, a separate component of stockholders' equity. Refer to Note 9 for a summary of changes in accumulated OCI for our available-for-sale securities for the three and nine months ended September 30, 2015 and 2014 . 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 September 30, 2015 and December 31, 2014 (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 September 30, 2015 $ 6,059 $ (30 ) $ 7,298 $ (115 ) $ 13,357 $ (145 ) December 31, 2014 $ 778 $ (2 ) $ 11,679 $ (186 ) $ 12,457 $ (188 ) We did not recognize any OTTI charges on our investment securities for the nine months ended September 30, 2015 and 2014 . 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 agency 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 agency securities upon selecting specific securities to sell. Gains and Losses The following table is a summary of our net gain (loss) from the sale of agency securities classified as available-for-sale for the three and nine months ended September 30, 2015 and 2014 (in millions): Three Months Ended September 30, Nine Months Ended September 30, Agency Securities Classified as Available-for-Sale 2015 2014 2015 2014 Agency MBS sold, at cost $ (4,575 ) $ (8,763 ) $ (22,548 ) $ (25,640 ) Proceeds from agency MBS sold 1 4,536 8,777 22,523 25,657 Net gain (loss) on sale of agency MBS $ (39 ) $ 14 $ (25 ) $ 17 Gross gain on sale of agency MBS $ 2 $ 41 $ 81 $ 132 Gross loss on sale of agency MBS (41 ) (27 ) (106 ) (115 ) Net gain (loss) on sale of agency MBS $ (39 ) $ 14 $ (25 ) $ 17 ________________________ 1. Proceeds include cash received during the period, plus receivable for agency MBS sold during the period as of period end. For the three and nine months ended September 30, 2015 , we recognized a net unrealized gain of $10 million and $14 million , respectively, and for the three and nine months ended September 30, 2014 we recognized a net unrealized gain of $4 million and $31 million , respectively, for the change in value of investments in interest and principal-only strips in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Over the same periods, we did not recognize any realized gains or losses on our interest or principal-only securities. Securitizations and Variable Interest Entities As of September 30, 2015 and December 31, 2014 , 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 MBS. 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 $1.1 billion and $1.3 billion as of September 30, 2015 and December 31, 2014 , respectively, and debt, at fair value, of $626 million and $761 million , respectively, in our accompanying consolidated balance sheets. As of September 30, 2015 and December 31, 2014 , the agency securities had an aggregate unpaid principal balance of $1.0 billion and $1.2 billion , respectively, and the debt had an aggregate unpaid principal balance of $621 million and $742 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 and nine months ended September 30, 2015 , we recorded a gain of $7 million and $16 million , respectively, associated with our consolidated debt. For the three and nine months ended September 30, 2014 , we recognized a net gain of $6 million and a net loss of $6 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 September 30, 2015 and December 31, 2014 , the fair value of our CMO securities and interest and principal-only securities was $1.4 billion and $1.6 billion , respectively, excluding the consolidated CMO trusts discussed above, or $1.9 billion and $2.1 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 $267 million and $274 million as of September 30, 2015 and December 31, 2014 , respectively." id="sjs-B4">Investment Securities As of September 30, 2015 and December 31, 2014 , our investment portfolio consisted of $54.8 billion and $56.7 billion of agency MBS, respectively, and a $7.4 billion and $14.8 billion net long TBA position, at fair value, respectively. Our TBA position is reported at its net carrying value of $120 million and $192 million as of September 30, 2015 and December 31, 2014 , 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 September 30, 2015 and December 31, 2014 .) As of September 30, 2015 and December 31, 2014 , the net unamortized premium balance on our agency MBS was $2.3 billion and $2.5 billion , respectively, including interest and principal-only strips. The following tables summarize our investments in agency MBS as of September 30, 2015 and December 31, 2014 (dollars in millions): September 30, 2015 Agency MBS Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Fixed rate $ 52,354 $ 653 $ (145 ) $ 52,862 Adjustable rate 535 16 — 551 CMO 1,010 31 — 1,041 Interest-only and principal-only strips 317 48 (2 ) 363 Total agency MBS $ 54,216 $ 748 $ (147 ) $ 54,817 December 31, 2014 Agency MBS Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Fixed rate $ 53,945 $ 715 $ (187 ) $ 54,473 Adjustable rate 659 19 — 678 CMO 1,172 24 (1 ) 1,195 Interest-only and principal-only strips 372 33 (3 ) 402 Total agency MBS $ 56,148 $ 791 $ (191 ) $ 56,748 September 30, 2015 Agency MBS Fannie Mae Freddie Mac Ginnie Mae Total Available-for-sale agency MBS: Agency MBS, par $ 39,898 $ 11,230 $ 559 $ 51,687 Unamortized discount (33 ) (4 ) — (37 ) Unamortized premium 1,718 523 8 2,249 Amortized cost 41,583 11,749 567 53,899 Gross unrealized gains 555 139 6 700 Gross unrealized losses (99 ) (46 ) — (145 ) Total available-for-sale agency MBS, at fair value 42,039 11,842 573 54,454 Agency MBS remeasured at fair value through earnings: Interest-only and principal-only strips, amortized cost 1 297 20 — 317 Gross unrealized gains 43 5 — 48 Gross unrealized losses (1 ) (1 ) — (2 ) Total agency MBS remeasured at fair value through earnings 339 24 — 363 Total agency MBS, at fair value $ 42,378 $ 11,866 $ 573 $ 54,817 Weighted average coupon as of September 30, 2015 2 3.60 % 3.67 % 3.05 % 3.61 % Weighted average yield as of September 30, 2015 3 2.76 % 2.77 % 2.66 % 2.76 % ________________________ 1. The underlying unamortized principal balance ("UPB" or "par value") of our interest-only agency MBS strips was $1.0 billion and the weighted average contractual interest we are entitled to receive was 5.42% of this amount as of September 30, 2015 . The par value of our principal-only agency MBS strips was $216 million as of September 30, 2015 . 2. The weighted average coupon includes the interest cash flows from our interest-only agency MBS strips taken together with the interest cash flows from our fixed rate, adjustable-rate and CMO agency MBS as a percentage of the par value of our agency MBS (excluding the UPB of our interest-only securities) as of September 30, 2015 . 3. Incorporates a weighted average future constant prepayment rate assumption of 9% based on forward rates as of September 30, 2015 . December 31, 2014 Agency MBS Fannie Mae Freddie Mac Ginnie Mae Total Available-for-sale agency MBS: Agency MBS, par $ 42,749 $ 10,566 $ 107 $ 53,422 Unamortized discount (37 ) (5 ) — (42 ) Unamortized premium 1,880 514 2 2,396 Amortized cost 44,592 11,075 109 55,776 Gross unrealized gains 610 145 3 758 Gross unrealized losses (127 ) (61 ) — (188 ) Total available-for-sale agency MBS, at fair value 45,075 11,159 112 56,346 Agency MBS measured at fair value through earnings: Interest-only and principal-only strips, amortized cost 1 348 24 — 372 Gross unrealized gains 30 3 — 33 Gross unrealized losses (2 ) (1 ) — (3 ) Total agency MBS measured at fair value through earnings 376 26 — 402 Total agency MBS, at fair value $ 45,451 $ 11,185 $ 112 $ 56,748 Weighted average coupon as of December 31, 2014 2 3.63 % 3.70 % 3.52 % 3.65 % Weighted average yield as of December 31, 2014 3 2.75 % 2.73 % 1.87 % 2.74 % ________________________ 1. The underlying UPB of our interest-only agency MBS strips was $1.2 billion and the weighted average contractual interest we are entitled to receive was 5.46% of this amount as of December 31, 2014 . The par value of our principal-only agency MBS strips was $242 million as of December 31, 2014 . 2. The weighted average coupon includes the interest cash flows from our interest-only agency MBS strips taken together with the interest cash flows from our fixed rate, adjustable-rate and CMO agency MBS as a percentage of the par value of our agency MBS (excluding the UPB of our interest-only securities) as of December 31, 2014 . 3. Incorporates a weighted average future constant prepayment rate assumption of 9% based on forward rates as of December 31, 2014 . The actual maturities of our agency MBS are generally shorter than the stated contractual maturities. Actual maturities are affected by the contractual lives of the underlying mortgages, periodic contractual principal payments and principal prepayments. As of September 30, 2015 and December 31, 2014 , our weighted average expected constant prepayment rate ("CPR") over the remaining life of our aggregate agency MBS portfolio was 9% . 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 agency MBS classified as available-for-sale as of September 30, 2015 and December 31, 2014 according to their estimated weighted average life classification (dollars in millions): September 30, 2015 December 31, 2014 Estimated Weighted Average Life of Agency MBS Classified as Available-for-Sale 1 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 $ 322 $ 316 3.67% 2.12% $ 289 $ 280 4.08% 2.62% > 3 years and ≤ 5 years 19,210 18,870 3.28% 2.40% 22,153 21,820 3.26% 2.40% > 5 years and ≤10 years 34,856 34,648 3.65% 2.91% 33,271 33,055 3.73% 2.92% > 10 years 66 65 3.78% 3.37% 633 621 3.28% 3.15% Total $ 54,454 $ 53,899 3.52% 2.72% $ 56,346 $ 55,776 3.54% 2.72% _______________________ 1. Excludes interest and principal-only strips. The weighted average life of our interest-only strips was 5.9 and 6.0 years as of September 30, 2015 and December 31, 2014 , respectively. The weighted average life of our principal-only strips was 7.8 and 8.1 years as of September 30, 2015 and December 31, 2014 , respectively. Securities classified as available-for-sale are reported at fair value, with unrealized gains and losses excluded from earnings and reported in accumulated OCI, a separate component of stockholders' equity. Refer to Note 9 for a summary of changes in accumulated OCI for our available-for-sale securities for the three and nine months ended September 30, 2015 and 2014 . 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 September 30, 2015 and December 31, 2014 (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 September 30, 2015 $ 6,059 $ (30 ) $ 7,298 $ (115 ) $ 13,357 $ (145 ) December 31, 2014 $ 778 $ (2 ) $ 11,679 $ (186 ) $ 12,457 $ (188 ) We did not recognize any OTTI charges on our investment securities for the nine months ended September 30, 2015 and 2014 . 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 agency 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 agency securities upon selecting specific securities to sell. Gains and Losses The following table is a summary of our net gain (loss) from the sale of agency securities classified as available-for-sale for the three and nine months ended September 30, 2015 and 2014 (in millions): Three Months Ended September 30, Nine Months Ended September 30, Agency Securities Classified as Available-for-Sale 2015 2014 2015 2014 Agency MBS sold, at cost $ (4,575 ) $ (8,763 ) $ (22,548 ) $ (25,640 ) Proceeds from agency MBS sold 1 4,536 8,777 22,523 25,657 Net gain (loss) on sale of agency MBS $ (39 ) $ 14 $ (25 ) $ 17 Gross gain on sale of agency MBS $ 2 $ 41 $ 81 $ 132 Gross loss on sale of agency MBS (41 ) (27 ) (106 ) (115 ) Net gain (loss) on sale of agency MBS $ (39 ) $ 14 $ (25 ) $ 17 ________________________ 1. Proceeds include cash received during the period, plus receivable for agency MBS sold during the period as of period end. For the three and nine months ended September 30, 2015 , we recognized a net unrealized gain of $10 million and $14 million , respectively, and for the three and nine months ended September 30, 2014 we recognized a net unrealized gain of $4 million and $31 million , respectively, for the change in value of investments in interest and principal-only strips in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Over the same periods, we did not recognize any realized gains or losses on our interest or principal-only securities. Securitizations and Variable Interest Entities As of September 30, 2015 and December 31, 2014 , 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 MBS. 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 $1.1 billion and $1.3 billion as of September 30, 2015 and December 31, 2014 , respectively, and debt, at fair value, of $626 million and $761 million , respectively, in our accompanying consolidated balance sheets. As of September 30, 2015 and December 31, 2014 , the agency securities had an aggregate unpaid principal balance of $1.0 billion and $1.2 billion , respectively, and the debt had an aggregate unpaid principal balance of $621 million and $742 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 and nine months ended September 30, 2015 , we recorded a gain of $7 million and $16 million , respectively, associated with our consolidated debt. For the three and nine months ended September 30, 2014 , we recognized a net gain of $6 million and a net loss of $6 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 September 30, 2015 and December 31, 2014 , the fair value of our CMO securities and interest and principal-only securities was $1.4 billion and $1.6 billion , respectively, excluding the consolidated CMO trusts discussed above, or $1.9 billion and $2.1 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 $267 million and $274 million as of September 30, 2015 and December 31, 2014 , respectively.

Repurchase Agreements And Other

Repurchase Agreements And Other Debt	9 Months Ended
	Sep. 30, 2015
Disclosure of Repurchase Agreements [Abstract]
Repurchase Agreements And Other Debt	90 days have floating interest rates based on an index plus or minus a fixed spread. As of September 30, 2015 and December 31, 2014 , $40.6 billion and $48.4 billion , respectively, of our repurchase agreements were used to fund purchases of agency securities ("agency repo"), with an average borrowing rate of 0.52% and 0.41% , respectively, and a weighted average remaining term to maturity of 201 and 143 days, respectively. The remainder, or $460 million and $1.9 billion , of our repurchase agreements as of September 30, 2015 and December 31, 2014 , respectively, were used to fund temporary holdings of U.S. Treasury securities ("U.S. Treasury repo"). The following table summarizes our borrowings under repurchase arrangements and weighted average interest rates classified by remaining maturities as of September 30, 2015 and December 31, 2014 (dollars in millions): September 30, 2015 December 31, 2014 Remaining Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Agency repo: ≤ 1 month $ 17,335 0.45 % 14 $ 14,157 0.37 % 15 > 1 to ≤ 3 months 10,209 0.52 % 59 20,223 0.38 % 61 > 3 to ≤ 6 months 5,167 0.54 % 135 6,654 0.42 % 120 > 6 to ≤ 9 months 1,963 0.59 % 208 1,575 0.50 % 225 > 9 to ≤ 12 months 500 0.64 % 292 2,678 0.54 % 313 > 12 to ≤ 24 months 1,078 0.61 % 634 600 0.57 % 551 > 24 to ≤ 36 months 1,252 0.66 % 812 952 0.60 % 999 > 36 to ≤ 48 months 1,350 0.75 % 1,254 650 0.64 % 1,266 > 48 to < 60 months 1,700 0.73 % 1,560 900 0.68 % 1,542 Total agency repo 40,554 0.52 % 201 48,389 0.41 % 143 U.S. Treasury repo: 1 day 208 0.38 % 1 1,907 0.09 % 1 > 1 day to ≤ 1 month 252 0.30 % 9 — — % — Total U.S. Treasury repo 460 0.34 % 5 1,907 0.09 % 1 Total $ 41,014 0.52 % 199 $ 50,296 0.40 % 138 Federal Home Loan Bank Advances In April 2015, our wholly-owned subsidiary, Old Georgetown Insurance Co., LLC ("OGI"), was accepted for membership in the Federal Home Loan Bank of Des Moines. As a member of the FHLB, OGI has access to a variety of products and services offered by the FHLB, including secured advances. The ability to borrow from the FHLB is subject to OGI's continued creditworthiness, pledging of sufficient eligible collateral to secure advances and compliance with certain agreements with the FHLB. Each advance requires approval by the FHLB and is secured by collateral in accordance with the FHLB’s credit and collateral guidelines, which may be revised from time to time by the FHLB. As of September 30, 2015 , OGI had $3.5 billion of outstanding secured FHLB advances, with a weighted average borrowing rate of 0.27% and a weighted average remaining term to maturity of 3.5 years, consisting of 30 day advances and longer-term floating rate advances with a one month cancellation feature: September 30, 2015 Remaining Maturity FHLB Advances Weighted Average Interest Rate Weighted Average Days to Maturity ≤ 1 month $ 753 0.27 % 6 > 9 to ≤ 12 months 245 0.35 % 322 > 36 to ≤ 48 months 411 0.26 % 1,419 > 48 to < 60 months 2,093 0.26 % 1,813 Total FHLB advances $ 3,502 0.27 % 1,274 Debt of Consolidated Variable Interest Entities As of September 30, 2015 and December 31, 2014 , debt of consolidated VIEs, at fair value, was $626 million and $761 million , respectively, and had a weighted average interest rate of LIBOR plus 40 and 43 basis points, respectively, and a principal balance of $621 million and $742 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 MBS 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 September 30, 2015 and December 31, 2014 was 4.6 and 5.8 years, respectively. TBA Dollar Roll Financing Transactions As of September 30, 2015 and December 31, 2014 , we had outstanding forward commitments to purchase and sell agency securities through the TBA market at a cost of $7.3 billion and $14.6 billion , respectively (see Notes 3 and 6 ). These transactions, also referred to as "TBA dollar roll transactions," represent a form of "off-balance sheet" financing and serve to either increase, in the case of forward purchases, or decrease, in the case of forward sales, our total "at risk" leverage. We account for such transactions as one or more series of derivative transactions and report our outstanding TBA commitments at their net carrying value of $120 million and $192 million as of September 30, 2015 and December 31, 2014 , respectively, in derivative assets/(liabilities) on our accompanying consolidated balance sheets." id="sjs-B4">Repurchase Agreements and Other Debt We pledge certain of our securities as collateral under our repurchase and other agreements with financial institutions and secured borrowing facility with the Federal Home Loan Bank ("FHLB") of Des Moines. Interest rates on our borrowings are generally based on LIBOR plus or minus a margin and amounts available to be borrowed are dependent upon the fair value of the securities pledged as collateral, which fluctuates with changes in interest rates, type of security and liquidity conditions within the banking, mortgage finance and real estate industries. If the fair value of our pledged securities declines, lenders will typically require us to post additional collateral or pay down borrowings to re-establish agreed upon collateral requirements, referred to as "margin calls." Similarly, if the fair value of our pledged securities increases, lenders may release collateral back to us. As of September 30, 2015 , we had met all margin call requirements. For additional information regarding our pledged assets, please refer to Note 7 . Repurchase Agreements As of September 30, 2015 and December 31, 2014 , we had $41.0 billion and $50.3 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 > 90 days have floating interest rates based on an index plus or minus a fixed spread. As of September 30, 2015 and December 31, 2014 , $40.6 billion and $48.4 billion , respectively, of our repurchase agreements were used to fund purchases of agency securities ("agency repo"), with an average borrowing rate of 0.52% and 0.41% , respectively, and a weighted average remaining term to maturity of 201 and 143 days, respectively. The remainder, or $460 million and $1.9 billion , of our repurchase agreements as of September 30, 2015 and December 31, 2014 , respectively, were used to fund temporary holdings of U.S. Treasury securities ("U.S. Treasury repo"). The following table summarizes our borrowings under repurchase arrangements and weighted average interest rates classified by remaining maturities as of September 30, 2015 and December 31, 2014 (dollars in millions): September 30, 2015 December 31, 2014 Remaining Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Agency repo: ≤ 1 month $ 17,335 0.45 % 14 $ 14,157 0.37 % 15 > 1 to ≤ 3 months 10,209 0.52 % 59 20,223 0.38 % 61 > 3 to ≤ 6 months 5,167 0.54 % 135 6,654 0.42 % 120 > 6 to ≤ 9 months 1,963 0.59 % 208 1,575 0.50 % 225 > 9 to ≤ 12 months 500 0.64 % 292 2,678 0.54 % 313 > 12 to ≤ 24 months 1,078 0.61 % 634 600 0.57 % 551 > 24 to ≤ 36 months 1,252 0.66 % 812 952 0.60 % 999 > 36 to ≤ 48 months 1,350 0.75 % 1,254 650 0.64 % 1,266 > 48 to < 60 months 1,700 0.73 % 1,560 900 0.68 % 1,542 Total agency repo 40,554 0.52 % 201 48,389 0.41 % 143 U.S. Treasury repo: 1 day 208 0.38 % 1 1,907 0.09 % 1 > 1 day to ≤ 1 month 252 0.30 % 9 — — % — Total U.S. Treasury repo 460 0.34 % 5 1,907 0.09 % 1 Total $ 41,014 0.52 % 199 $ 50,296 0.40 % 138 Federal Home Loan Bank Advances In April 2015, our wholly-owned subsidiary, Old Georgetown Insurance Co., LLC ("OGI"), was accepted for membership in the Federal Home Loan Bank of Des Moines. As a member of the FHLB, OGI has access to a variety of products and services offered by the FHLB, including secured advances. The ability to borrow from the FHLB is subject to OGI's continued creditworthiness, pledging of sufficient eligible collateral to secure advances and compliance with certain agreements with the FHLB. Each advance requires approval by the FHLB and is secured by collateral in accordance with the FHLB’s credit and collateral guidelines, which may be revised from time to time by the FHLB. As of September 30, 2015 , OGI had $3.5 billion of outstanding secured FHLB advances, with a weighted average borrowing rate of 0.27% and a weighted average remaining term to maturity of 3.5 years, consisting of 30 day advances and longer-term floating rate advances with a one month cancellation feature: September 30, 2015 Remaining Maturity FHLB Advances Weighted Average Interest Rate Weighted Average Days to Maturity ≤ 1 month $ 753 0.27 % 6 > 9 to ≤ 12 months 245 0.35 % 322 > 36 to ≤ 48 months 411 0.26 % 1,419 > 48 to < 60 months 2,093 0.26 % 1,813 Total FHLB advances $ 3,502 0.27 % 1,274 Debt of Consolidated Variable Interest Entities As of September 30, 2015 and December 31, 2014 , debt of consolidated VIEs, at fair value, was $626 million and $761 million , respectively, and had a weighted average interest rate of LIBOR plus 40 and 43 basis points, respectively, and a principal balance of $621 million and $742 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 MBS 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 September 30, 2015 and December 31, 2014 was 4.6 and 5.8 years, respectively. TBA Dollar Roll Financing Transactions As of September 30, 2015 and December 31, 2014 , we had outstanding forward commitments to purchase and sell agency securities through the TBA market at a cost of $7.3 billion and $14.6 billion , respectively (see Notes 3 and 6 ). These transactions, also referred to as "TBA dollar roll transactions," represent a form of "off-balance sheet" financing and serve to either increase, in the case of forward purchases, or decrease, in the case of forward sales, our total "at risk" leverage. We account for such transactions as one or more series of derivative transactions and report our outstanding TBA commitments at their net carrying value of $120 million and $192 million as of September 30, 2015 and December 31, 2014 , respectively, in derivative assets/(liabilities) on our accompanying consolidated balance sheets.

Derivative and Other Hedging In

Derivative and Other Hedging Instruments	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative and Other Hedging Instruments	Derivative and Other Hedging Instruments In connection with our risk management strategy, we hedge a portion of our interest rate risk by entering into derivative and other hedging instrument contracts. We typically enter into agreements for interest rate swaps and interest rate swaptions and purchase or short TBA and U.S. Treasury securities. We may also purchase or write put or call options on TBA securities or invest in mortgage and other types of derivative instruments, such as interest and principal-only securities. 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 . Prior to September 30, 2011, our interest rate swaps were typically designated as cash flow hedges under ASC 815; however, as of September 30, 2011, we elected to discontinue hedge accounting for our interest rate swaps in order to increase our funding flexibility. For the three and nine months ended September 30, 2015 , we reclassified $24 million and $79 million , respectively, and for the three and nine months ended September 30, 2014 , we reclassified, $38 million and $121 million , respectively, of net deferred losses from accumulated OCI into interest expense related to our de-designated interest rate swaps and recognized an equal, but offsetting, amount in other comprehensive income. Our total net periodic interest costs on our swap portfolio was $131 million and $369 million for the three and nine months ended September 30, 2015 , respectively, and $120 million and $373 million for the three and nine months ended September 30, 2014 , respectively. The difference between our total net periodic interest costs on our swap portfolio and the amount recorded in interest expense related to our de-designated hedges is reported in our accompanying consolidated statements of comprehensive income in gain (loss) on derivative instruments and other securities, net (totaling $107 million and $290 million for the three and nine months ended September 30, 2015 , respectively, and $82 million and $252 million for the three and nine months ended September 30, 2014 , respectively). As of September 30, 2015 , the remaining net deferred loss in accumulated OCI related to de-designated interest rate swaps was $61 million and will be reclassified from OCI into interest expense over a remaining weighted average period of 0.8 years. As of September 30, 2015 , the net deferred loss expected to be reclassified from OCI into interest expense over the next twelve months was $58 million . 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 and liabilities as of September 30, 2015 and December 31, 2014 (in millions): Derivative and Other Hedging Instruments Balance Sheet Location September 30, 2015 December 31, 2014 Interest rate swaps Derivative assets, at fair value $ — $ 136 Swaptions Derivative assets, at fair value 21 75 TBA securities Derivative assets, at fair value 122 197 Total derivative assets, at fair value $ 143 $ 408 Interest rate swaps Derivative liabilities, at fair value $ (1,523 ) $ (880 ) TBA securities Derivative liabilities, at fair value (2 ) (5 ) U.S. Treasury futures - short Derivative liabilities, at fair value (9 ) (5 ) Other Derivative liabilities, at fair value (2 ) — Total derivative liabilities, at fair value $ (1,536 ) $ (890 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ 787 $ 2,427 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (1,309 ) (5,363 ) Total - U.S. Treasury securities, net at fair value $ (522 ) $ (2,936 ) The following tables summarize our interest rate swap agreements outstanding as of September 30, 2015 and December 31, 2014 (dollars in millions): September 30, 2015 Payer Interest Rate Swaps Notional Amount 1 Average Fixed Pay Rate 2 Average Receive Rate 3 Net Estimated Fair Value Average Maturity (Years) ≤ 3 years $ 16,725 1.21% 0.29% $ (133 ) 1.6 > 3 to ≤ 5 years 9,450 1.93% 0.32% (277 ) 4.1 > 5 to ≤ 7 years 8,425 2.43% 0.32% (373 ) 6.2 > 7 to ≤ 10 years 9,050 2.67% 0.31% (588 ) 8.2 > 10 years 1,525 3.21% 0.32% (152 ) 13.9 Total Payer Interest Rate Swaps $ 45,175 1.95% 0.30% $ (1,523 ) 4.7 ________________________ 1. Notional amount includes forward starting swaps of $7.8 billion with an average forward start date of 0.6 years and an average maturity of 6.3 years from September 30, 2015 . 2. Average fixed pay rate includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.72% as of September 30, 2015 . 3. Average receive rate excludes forward starting swaps. December 31, 2014 Payer Interest Rate Swaps Notional 1 Average 2 Average 3 Net Average ≤ 3 years $ 12,300 1.33% 0.21% $ (87 ) 2.0 > 3 to ≤ 5 years 8,975 1.63% 0.24% (4 ) 4.2 > 5 to ≤ 7 years 7,250 2.47% 0.23% (139 ) 6.1 > 7 to ≤ 10 years 10,775 2.48% 0.24% (223 ) 8.3 > 10 years 4,400 3.19% 0.23% (291 ) 12.6 Total Payer Interest Rate Swaps $ 43,700 2.05% 0.23% $ (744 ) 5.8 ________________________ 1. Notional amount includes forward starting swaps of $12.4 billion with an average forward start date of 1.1 years and an average maturity of 7.9 years from December 31, 2014 . 2. Average fixed pay rate includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.68% as of December 31, 2014 . 3. Average receive rate excludes forward starting swaps. The following table summarizes our interest rate payer swaption agreements outstanding as of September 30, 2015 and December 31, 2014 (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) September 30, 2015 ≤ 1 year $ 95 $ 21 5 $ 3,650 3.35% 3M 8.2 December 31, 2014 ≤ 1 year $ 113 $ 36 6 $ 5,600 3.15% 3M 6.4 > 1 to ≤ 2 years 32 10 16 1,200 3.87% 3M 5.1 Total Payer Swaptions $ 145 $ 46 8 $ 6,800 3.28% 3M 6.2 The following table summarizes our interest rate receiver swaption agreements outstanding as of December 31, 2014 (dollars in millions). We had no interest rate receiver swaptions outstanding as of September 30, 2015 . Receiver Swaptions Option Underlying Receiver Swap Years to Expiration Cost Fair Value Average Months to Expiration Notional Amount Average Fixed Receive Rate Average Pay Rate (LIBOR) Average Term (Years) December 31, 2014 ≤ 1 year $ 18 $ 29 5 $ 4,250 1.78% 3M 6.4 The following table summarizes our U.S. Treasury securities as of September 30, 2015 and December 31, 2014 (in millions): September 30, 2015 December 31, 2014 Maturity Face Amount Net Long / (Short) Cost Basis Market Value Face Amount Net Long / (Short) Cost Basis Market Value 5 years $ 597 $ 604 $ 605 $ (4,674 ) $ (4,650 ) $ (4,645 ) 7 years (90 ) (89 ) (88 ) (717 ) (717 ) (718 ) 10 years (1,033 ) (1,028 ) (1,039 ) 2,410 2,422 2,427 Total U.S. Treasury securities, net $ (526 ) $ (513 ) $ (522 ) $ (2,981 ) $ (2,945 ) $ (2,936 ) The following tables summarize our TBA securities as of September 30, 2015 and December 31, 2014 (in millions): September 30, 2015 December 31, 2014 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% $ (409 ) $ (414 ) $ (417 ) $ (3 ) $ 962 $ 968 $ 980 $ 12 3.0% 143 148 149 1 2,779 2,889 2,888 (1 ) 3.5% 4 4 4 — (468 ) (495 ) (494 ) 1 4.0% — — — — (13 ) (14 ) (14 ) — Total 15-Year TBAs (262 ) (262 ) (264 ) (2 ) 3,260 3,348 3,360 12 30-Year TBA securities: 3.0% 3,441 3,424 3,480 56 5,254 5,259 5,313 54 3.5% 1,873 1,900 1,954 54 7,902 8,151 8,232 81 4.0% 2,076 2,203 2,215 12 (1,853 ) (2,019 ) (1,974 ) 45 4.5% — — — — (151 ) (163 ) (163 ) — Total 30-Year TBAs 7,390 7,527 7,649 122 11,152 11,228 11,408 180 Total net TBA securities $ 7,128 $ 7,265 $ 7,385 $ 120 $ 14,412 $ 14,576 $ 14,768 $ 192 September 30, 2015 December 31, 2014 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 $ 6,572 $ 6,698 $ 6,807 $ 109 $ 15,127 $ 15,316 $ 15,509 $ 193 Freddie Mac 256 255 264 9 (715 ) (740 ) (741 ) (1 ) Ginnie Mae 300 312 314 2 — — — — TBA securities, net $ 7,128 $ 7,265 $ 7,385 $ 120 $ 14,412 $ 14,576 $ 14,768 $ 192 _____________________ 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 and nine months ended September 30, 2015 and 2014 (in millions): Three Months Ended September 30, 2015 Derivative and Other Hedging Instruments Notional Amount Long/(Short) June 30, 2015 Additions Settlement, Termination, Expiration or Exercise Notional Amount Long/(Short) September 30, 2015 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 6,941 33,403 (33,216 ) $ 7,128 $ 213 Interest rate swaps $ (44,925 ) (1,450 ) 1,200 $ (45,175 ) (966 ) Payer swaptions $ (5,450 ) — 1,800 $ (3,650 ) (23 ) U.S. Treasury securities - short position $ (2,250 ) (4,335 ) 5,284 $ (1,301 ) (25 ) U.S. Treasury securities - long position $ 5,192 4,704 (9,121 ) $ 775 29 U.S. Treasury futures contracts - short position $ (730 ) (730 ) 730 $ (730 ) (23 ) $ (795 ) ________________________________ 1. Excludes a net gain of $7 million from debt of consolidated VIEs and a net gain of $10 million from interest and principal-only securities recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Three Months Ended September 30, 2014 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount Long/(Short) September 30, 2014 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 17,811 44,438 (44,990 ) $ 17,259 $ 33 Interest rate swaps $ (47,900 ) (3,625 ) 11,300 $ (40,225 ) (26 ) Payer swaptions $ (7,650 ) (1,500 ) 3,000 $ (6,150 ) (14 ) Receiver swaptions $ 1,750 750 — $ 2,500 — U.S. Treasury securities - short position $ (5,988 ) (5,974 ) 7,263 $ (4,699 ) (44 ) U.S. Treasury securities - long position $ 1,250 5,028 (5,055 ) $ 1,223 (8 ) U.S. Treasury futures contracts - short position $ (730 ) (730 ) 730 $ (730 ) — TBA put option $ (100 ) — 100 $ — — $ (59 ) ______________________ 1. Excludes a net loss of $2 million from investments in REIT equity securities, a net gain of $6 million from debt of consolidated VIEs and a net gain of $4 million from interest and principal-only securities recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Nine Months Ended September 30, 2015 Derivative and Other Hedging Instruments Notional Amount Long/(Short) December 31, 2014 Additions Settlement, Termination, Expiration or Exercise Notional Amount Long/(Short) September 30, 2015 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 14,412 97,270 (104,554 ) $ 7,128 $ 337 Interest rate swaps $ (43,700 ) (4,950 ) 3,475 $ (45,175 ) (1,278 ) Payer swaptions $ (6,800 ) (500 ) 3,650 $ (3,650 ) (27 ) Receiver swaptions $ 4,250 — (4,250 ) $ — 4 U.S. Treasury securities - short position $ (5,392 ) (10,732 ) 14,823 $ (1,301 ) (89 ) U.S. Treasury securities - long position $ 2,411 31,915 (33,551 ) $ 775 (35 ) U.S. Treasury futures contracts - short position $ (730 ) (2,190 ) 2,190 $ (730 ) (28 ) $ (1,116 ) ________________________________ 1. Excludes a net gain of $16 million from debt of consolidated VIEs, a net gain of $14 million from interest and principal-only securities and other miscellaneous net losses of $4 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Nine Months Ended September 30, 2014 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount Long/(Short) September 30, 2014 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 2,119 134,760 (119,620 ) $ 17,259 $ 637 Interest rate swaps $ (43,250 ) (12,325 ) 15,350 $ (40,225 ) (993 ) Payer swaptions $ (14,250 ) (3,750 ) 11,850 $ (6,150 ) (160 ) Receiver swaptions $ — 2,500 — $ 2,500 — U.S. Treasury securities - short position $ (2,007 ) (21,830 ) 19,138 $ (4,699 ) (262 ) U.S. Treasury securities - long position $ 3,927 9,963 (12,667 ) $ 1,223 72 U.S. Treasury futures contracts - short position $ (1,730 ) (2,190 ) 3,190 $ (730 ) (55 ) TBA put option $ — (150 ) 150 $ — — $ (761 ) ______________________ 1. Excludes a net gain of $71 million from investments in REIT equity securities, a net loss of $6 million from debt of consolidated VIEs, a net gain of $31 million from interest and principal-only securities and other miscellaneous net losses of $7 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income.

Pledged Assets

Pledged Assets	9 Months Ended
	Sep. 30, 2015
Pledged Assets [Abstract]
Pledged Assets	30 and ≤ 60 days 5,626 5,582 16 10,906 10,784 30 > 60 and ≤ 90 days 4,820 4,774 13 10,205 10,109 28 > 90 days 17,552 17,375 49 15,267 15,096 43 Total agency MBS 46,798 46,279 129 51,037 50,498 142 U.S. Treasury securities: 1 day 209 207 — 1,904 1,899 5 > 1 day ≤ 30 days 253 253 1 — — — Total U.S. Treasury securities 462 460 1 1,904 1,899 5 Total $ 47,260 $ 46,739 $ 130 $ 52,941 $ 52,397 $ 147 ______________________ 1. Includes $256 million and $179 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements, as of September 30, 2015 and December 31, 2014 , respectively. As of September 30, 2015 and December 31, 2014 , none of our borrowings backed by agency MBS 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 September 30, 2015 and December 31, 2014 , we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions). September 30, 2015 December 31, 2014 Assets Pledged to AGNC Reverse Repurchase Agreements Derivative Agreements Total Reverse Repurchase Agreements Derivative Agreements Total Agency MBS - fair value $ — $ — $ — $ — $ 43 $ 43 U.S. Treasury securities - fair value 1,309 — 1,309 5,363 47 5,410 Cash — — — — 28 28 Total $ 1,309 $ — $ 1,309 $ 5,363 $ 118 $ 5,481 U.S Treasury securities received as collateral under our reverse repurchase agreements are accounted for as securities borrowing transactions and are used to cover short sales of the same securities. 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 such arrangements and can potentially be offset on our consolidated balance sheets as of September 30, 2015 and December 31, 2014 (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 September 30, 2015 Interest rate swap and swaption agreements, at fair value 1 $ 21 $ — $ 21 $ (21 ) $ — $ — Receivable under reverse repurchase agreements 1,463 — 1,463 (1,459 ) (4 ) — Total $ 1,484 $ — $ 1,484 $ (1,480 ) $ (4 ) $ — December 31, 2014 Interest rate swap and swaption agreements, at fair value 1 $ 211 $ — $ 211 $ (94 ) $ (83 ) $ 34 Receivable under reverse repurchase agreements 5,218 — 5,218 (4,690 ) (528 ) — Total $ 5,429 $ — $ 5,429 $ (4,784 ) $ (611 ) $ 34 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 September 30, 2015 Interest rate swap agreements, at fair value 1 $ 1,523 $ — $ 1,523 $ (21 ) $ (1,502 ) $ — Repurchase agreements and FHLB advances 44,516 — 44,516 (1,459 ) (43,057 ) — Total $ 46,039 $ — $ 46,039 $ (1,480 ) $ (44,559 ) $ — December 31, 2014 Interest rate swap agreements, at fair value 1 $ 880 $ — $ 880 $ (94 ) $ (782 ) $ 4 Repurchase agreements 50,296 — 50,296 (4,690 ) (45,606 ) — Total $ 51,176 $ — $ 51,176 $ (4,784 ) $ (46,388 ) $ 4 _______________________ 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 interest rate swap agreements and TBA contracts. 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. Additionally, the FHLB of Des Moines may adjust the haircut on our outstanding FHLB advances at any time prior to maturity. As a condition of our membership in the FHLB of Des Moines, we are also obligated to purchase membership and activity-based stock in the FHLB based upon the aggregate amount of advances obtained from the FHLB. 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 above certain specified levels. As of September 30, 2015 , 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 September 30, 2015 , our maximum amount at risk with any counterparty related to our repurchase agreements was 6% of our stockholders' equity and our 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 September 30, 2015 (dollars in millions). As of December 31, 2014 , the maximum amount at risk with any counterparty related to our repurchase agreements was less than 5% of our stockholders' equity. September 30, 2015 Amount Outstanding Net Counterparty Exposure 1 Percent of Equity Weighted Average Days to Maturity J.P. Morgan Securities, LLC $ 4,585 $ 496 6 % 1,076 _______________________ 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. Payables due to broker counterparties for unsettled securities purchases are not included in the amounts presented above. As of September 30, 2015 , we did not have any such payables. 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 September 30, 2015 and December 31, 2014 (in millions): September 30, 2015 Assets Pledged to Counterparties Repurchase Agreements and FHLB Advances 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements Total Agency MBS - fair value $ 46,798 $ 1,088 $ 247 $ 531 $ 48,664 U.S. Treasury securities - fair value 462 — 452 — 914 Accrued interest on pledged securities 130 3 2 2 137 Restricted cash 26 — 1,356 31 1,413 Total $ 47,416 $ 1,091 $ 2,057 $ 564 $ 51,128 ______________________ 1. Includes $256 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements. December 31, 2014 Assets Pledged to Counterparties Repurchase Agreements 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements Total Agency MBS - fair value $ 51,037 $ 1,266 $ 69 $ 702 $ 53,074 U.S. Treasury securities - fair value 1,904 — 550 — 2,454 Accrued interest on pledged securities 147 4 2 — 153 Restricted cash 6 — 698 9 713 Total $ 53,094 $ 1,270 $ 1,319 $ 711 $ 56,394 ______________________ 1. Includes $179 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements. As of September 30, 2015, we held $140 million of membership and activity-based stock in the FHLB of Des Moines. FHLB stock is reported at cost, which equals par value, in other assets on our accompanying consolidated balance sheets. FHLB stock can only be redeemed or sold at its par value, and only to the FHLB of Des Moines. The cash and cash equivalents and agency securities pledged as collateral under our derivative agreements are included in restricted cash and 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 September 30, 2015 and December 31, 2014 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 5 . September 30, 2015 December 31, 2014 Agency 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 Agency MBS: 1 ≤ 30 days $ 18,800 $ 18,548 $ 51 $ 14,659 $ 14,509 $ 41 > 30 and ≤ 60 days 5,626 5,582 16 10,906 10,784 30 > 60 and ≤ 90 days 4,820 4,774 13 10,205 10,109 28 > 90 days 17,552 17,375 49 15,267 15,096 43 Total agency MBS 46,798 46,279 129 51,037 50,498 142 U.S. Treasury securities: 1 day 209 207 — 1,904 1,899 5 > 1 day ≤ 30 days 253 253 1 — — — Total U.S. Treasury securities 462 460 1 1,904 1,899 5 Total $ 47,260 $ 46,739 $ 130 $ 52,941 $ 52,397 $ 147 ______________________ 1. Includes $256 million and $179 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements, as of September 30, 2015 and December 31, 2014 , respectively. As of September 30, 2015 and December 31, 2014 , none of our borrowings backed by agency MBS 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 September 30, 2015 and December 31, 2014 , we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions). September 30, 2015 December 31, 2014 Assets Pledged to AGNC Reverse Repurchase Agreements Derivative Agreements Total Reverse Repurchase Agreements Derivative Agreements Total Agency MBS - fair value $ — $ — $ — $ — $ 43 $ 43 U.S. Treasury securities - fair value 1,309 — 1,309 5,363 47 5,410 Cash — — — — 28 28 Total $ 1,309 $ — $ 1,309 $ 5,363 $ 118 $ 5,481 U.S Treasury securities received as collateral under our reverse repurchase agreements are accounted for as securities borrowing transactions and are used to cover short sales of the same securities. 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 such arrangements and can potentially be offset on our consolidated balance sheets as of September 30, 2015 and December 31, 2014 (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 September 30, 2015 Interest rate swap and swaption agreements, at fair value 1 $ 21 $ — $ 21 $ (21 ) $ — $ — Receivable under reverse repurchase agreements 1,463 — 1,463 (1,459 ) (4 ) — Total $ 1,484 $ — $ 1,484 $ (1,480 ) $ (4 ) $ — December 31, 2014 Interest rate swap and swaption agreements, at fair value 1 $ 211 $ — $ 211 $ (94 ) $ (83 ) $ 34 Receivable under reverse repurchase agreements 5,218 — 5,218 (4,690 ) (528 ) — Total $ 5,429 $ — $ 5,429 $ (4,784 ) $ (611 ) $ 34 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 September 30, 2015 Interest rate swap agreements, at fair value 1 $ 1,523 $ — $ 1,523 $ (21 ) $ (1,502 ) $ — Repurchase agreements and FHLB advances 44,516 — 44,516 (1,459 ) (43,057 ) — Total $ 46,039 $ — $ 46,039 $ (1,480 ) $ (44,559 ) $ — December 31, 2014 Interest rate swap agreements, at fair value 1 $ 880 $ — $ 880 $ (94 ) $ (782 ) $ 4 Repurchase agreements 50,296 — 50,296 (4,690 ) (45,606 ) — Total $ 51,176 $ — $ 51,176 $ (4,784 ) $ (46,388 ) $ 4 _______________________ 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	9 Months Ended
	Sep. 30, 2015
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 hierarchy levels during the three and nine months ended September 30, 2015 . The three levels of hierarchy are defined as follows: • Level 1 Inputs —Quoted prices (unadjusted) for identical unrestricted assets and liabilities in active markets that are accessible at the measurement date. • Level 2 Inputs —Quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. • Level 3 Inputs —Instruments with primarily unobservable market data that cannot be corroborated. The following table provides a summary of our assets and liabilities that are measured at fair value on a recurring basis as of September 30, 2015 and December 31, 2014 (in millions): September 30, 2015 December 31, 2014 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 53,729 $ — $ — $ 55,482 $ — Agency securities transferred to consolidated VIEs — 1,088 — — 1,266 — U.S. Treasury securities 787 — — 2,427 — — Interest rate swaps — — — — 136 — Swaptions — 21 — — 75 — REIT equity securities 34 — — 68 — — TBA securities — 122 — — 197 — Total $ 821 $ 54,960 $ — $ 2,495 $ 57,156 $ — Liabilities: Debt of consolidated VIEs $ — $ 626 $ — $ — $ 761 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 1,309 — — 5,363 — — Interest rate swaps — 1,523 — — 880 — TBA securities — 2 — — 5 — U.S. Treasury futures 9 — — 5 — — Other — 2 — — — — Total $ 1,318 $ 2,153 $ — $ 5,368 $ 1,646 $ — 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 the fair value of the agency MBS transferred to consolidated VIEs, less the fair value of our retained interests, which are based on valuations obtained from third-party pricing services and non-binding dealer quotes derived from common market pricing methods using "Level 2" inputs. Excluded from the table above are financial instruments, including cash and cash equivalents, restricted cash, 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 2" inputs.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2015
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 September 30, 2015 , we had 3.1 million shares of authorized but unissued shares of preferred stock. Our Board of Directors may designate additional series of authorized preferred stock ranking junior to or in parity with the Series A or Series B Preferred Stock or designate additional shares of the Series A or Series B Preferred Stock and authorize the issuance of such shares. In April 2012 , we completed a public offering in which 6.9 million shares of our Series A Preferred Stock were sold to the underwriters at a price of $24.2125 per share for proceeds, net of offering expenses, of $167 million . In May 2014 , we completed a public offering in which 7.0 million depositary shares were sold to the underwriters at a price of $24.2125 per depositary share for proceeds, net of offering expenses, of $169 million . Each depositary share represents a 1/1,000th interest in a share of our Series B Preferred Stock. Our Series A and Series B Preferred Stock have no stated maturity, are not subject to any sinking fund or mandatory redemption and rank on parity with each other. Under certain circumstances upon a change of control, our Series A and Series B Preferred Stock are convertible to shares of our common stock. Holders of our Series A Preferred Stock and depository shares underlying our Series B Preferred Stock have no voting rights, except under limited conditions, and are entitled to receive cumulative cash dividends at a rate of 8.000% and 7.750% per annum, respectively, of their $25.00 per share and $25.00 per depositary share liquidation preference, respectively, before holders of our common stock are entitled to receive any dividends. Shares of our Series A Preferred Stock and depository shares underlying our Series B Preferred Stock are each redeemable at $25.00 per share, plus accumulated and unpaid dividends (whether or not declared) exclusively at our option commencing on April 5, 2017 and May 8, 2019 , respectively, or earlier under certain circumstances intended to preserve our qualification as a REIT for federal income tax purposes. Dividends are payable quarterly in arrears on the 15th day of each January, April, July and October. As of September 30, 2015 , we had declared all required quarterly dividends on our Series A and Series B Preferred Stock. Common Stock Repurchase Program Our Board of Directors adopted a program that authorizes repurchases of our common stock up to a specified amount. In October 2015, our Board of Directors extended its authorization through December 31, 2016. Shares of our common stock may be purchased in the open market, including through block purchases, or through privately negotiated transactions, or pursuant to any trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended. The timing, manner, price and amount of any repurchases will be determined at our discretion and the program may be suspended, terminated or modified at any time for any reason. Among other factors, we intend to only consider repurchasing shares of our common stock when the purchase price is less than our estimate of our current net asset value per common share. Generally, when we repurchase our common stock at a discount to our net asset value, the net asset value of our remaining shares of common stock outstanding increases. In addition, we do not intend to repurchase any shares from directors, officers or other affiliates. The program does not obligate us to acquire any specific number of shares, and all repurchases will be made in accordance with Rule 10b-18, which sets certain restrictions on the method, timing, price and volume of stock repurchases. During the three and nine months ended September 30, 2015 , we repurchased approximately 2.4 million and 6.3 million shares, respectively, of our common stock at an average repurchase price of $19.08 and $19.57 per share, respectively, including expenses, totaling $45 million and $124 million , respectively. During the nine months ended September 30, 2014 , we repurchased approximately 3.4 million shares of our common stock at an average repurchase price of $22.10 per share, including expenses, totaling $74 million . We did not repurchase any shares of our common stock during the three months ended September 30, 2014 . As of September 30, 2015 , the total remaining amount authorized for repurchases of our common stock was $868 million . Accumulated Other Comprehensive Income (Loss) The following table summarizes changes to accumulated OCI for the three and nine months ended September 30, 2015 and 2014 (in millions): Accumulated Other Comprehensive Income (Loss) Net Unrealized Gain (Loss) on Available-for-Sale MBS Net Unrealized Gain (Loss) on Swaps Total Accumulated OCI Balance Three Months Ended September 30, 2015 Balance as of June 30, 2015 $ 89 $ (85 ) $ 4 OCI before reclassifications 428 — 428 Amounts reclassified from accumulated OCI 39 24 63 Balance as of September 30, 2015 $ 556 $ (61 ) $ 495 Three Months Ended September 30, 2014 Balance as of June 30, 2014 $ 225 $ (213 ) $ 12 OCI before reclassifications (239 ) — (239 ) Amounts reclassified from accumulated OCI (14 ) 38 24 Balance as of September 30, 2014 $ (28 ) $ (175 ) $ (203 ) Nine Months Ended September 30, 2015 Balance as of December 31, 2014 $ 570 $ (140 ) $ 430 OCI before reclassifications (39 ) — (39 ) Amounts reclassified from accumulated OCI 25 79 104 Balance as of September 30, 2015 $ 556 $ (61 ) $ 495 Nine Months Ended September 30, 2014 Balance as of December 31, 2013 $ (1,087 ) $ (296 ) $ (1,383 ) OCI before reclassifications 1,076 — 1,076 Amounts reclassified from accumulated OCI (17 ) 121 104 Balance as of September 30, 2014 $ (28 ) $ (175 ) $ (203 ) The following table summarizes reclassifications out of accumulated OCI for the three and nine months ended September 30, 2015 and 2014 (in millions): Three Months Ended September 30, Nine Months Ended September 30, Line Item in the Consolidated Statements of Comprehensive Income Where Net Income is Presented Amounts Reclassified from Accumulated OCI 2015 2014 2015 2014 (Gain) loss amounts reclassified from accumulated OCI for available-for-sale MBS upon realization $ 39 $ (14 ) $ 25 $ (17 ) Gain (loss) on sale of agency securities, net Periodic interest costs of interest rate swaps previously designated as hedges under GAAP, net 24 38 79 121 Interest expense Total reclassifications $ 63 $ 24 $ 104 $ 104

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Event	Subsequent Events On October 13, 2015 , our Board of Directors declared a monthly dividend of $0.20 per common share, which will be paid on November 9, 2015 , to common stockholders of record as of October 30, 2015 .

Summary of Significant Accoun17

Summary of Significant Accounting Policies (Policy)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Investment Securities	Investment Securities ASC Topic 320, Investments—Debt and Equity Securities ("ASC 320"), 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. Securities classified as trading and available-for-sale are reported at fair value, while securities classified as held-to-maturity are reported at amortized cost. We may sell any of our securities as part of our overall management of our investment portfolio. Accordingly, we typically designate our agency and AAA non-agency securities as available-for-sale. All securities classified as available-for-sale are reported at fair value, with unrealized gains and losses reported in accumulated other comprehensive income (loss) ("OCI"), a separate component of stockholders' equity. Upon the sale of a security, 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. Interest-only securities and inverse interest-only securities (collectively referred to as "interest-only securities") represent our right to receive a specified proportion of the contractual interest cash flows of specific agency CMO securities. Principal-only securities represent our right to receive the contractual principal cash flows of specific agency CMO securities. Interest and principal-only securities are measured at fair value through earnings in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Our investments in interest and principal-only securities are included in agency securities, at fair value on the accompanying consolidated balance sheets. REIT equity securities represent investments in the common stock of other publicly traded mortgage REITs that invest predominantly in agency MBS. We designate our investments in REIT equity securities as trading securities and report them at fair value on the accompanying consolidated balance sheets. We estimate the fair value of our agency and AAA non-agency securities based on valuations obtained from third-party pricing services and non-binding dealer quotes derived from common market pricing methods using observable (or "Level 2") inputs. Such methods incorporate, but are not limited to, reported trades and executable bid and asked prices for similar securities, benchmark interest rate curves, such as the spread to the U.S. Treasury rate and interest rate swap curves, convexity, duration and the underlying characteristics of the particular security, including coupon, periodic and life caps, rate reset period, issuer, additional credit support and expected life of the security. We estimate the fair value of our REIT equity securities based on a market approach using quoted market prices (or "Level 1" inputs). Refer to Note 8 for further discussion of fair value measurements. We evaluate our investment securities 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. The liquidity of the agency and AAA non-agency securities market allows us to obtain competitive bids and execute on a sale transaction typically within one to two days of making the decision to sell a security and, therefore, we generally do not make decisions to sell specific securities until shortly prior to initiating a sell order. In some instances, we may sell specific agency securities by delivering such securities into existing short to-be-announced ("TBA") contracts. TBA market conventions require the identification of the specific agency securities to be delivered no later than 48 hours prior to settlement. If we settle a short TBA contract through the delivery of securities, we will generally identify the specific securities to be delivered within one to two days of the 48-hour deadline.
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 investment securities 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 ("ASC 310-20"). We estimate long-term prepayment speeds of our agency and AAA non-agency securities using a third-party service and market data. The third-party service estimates prepayment speeds using models that incorporate the forward yield curve, current mortgage rates and mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, volatility and other factors. We review the prepayment speeds estimated by the third-party service and compare the results to market consensus prepayment speeds, if available. We also consider historical prepayment speeds and current market conditions to validate the reasonableness of the prepayment speeds estimated by the third-party service. As market conditions may change rapidly, we may make adjustments for different securities based on our Manager's judgment. Various market participants could use materially different assumptions. 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.
Derivative Instruments	Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate risk, prepayment risk and extension 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 forward contracts for the purchase or sale of agency MBS securities in the "to-be-announced" market ("TBA securities"), U.S. Treasury securities and U.S. Treasury futures contracts. We may also purchase or write put or call options on TBA securities and invest in mortgage and other types of derivative instruments, such as interest and principal-only securities. We may 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). Pursuant to 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 the balance sheet and to measure those instruments at fair value. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with the counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. Derivative instruments in a gain position are reported as derivative assets at fair value and derivative instruments in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Changes in fair value of derivative instruments and periodic settlements related to our derivative instruments are recorded in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized in the event that the counterparties to these instruments fail to perform their obligations under the contracts. We attempt to minimize this risk by limiting our counterparties to major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Discontinuation of hedge accounting for interest rate swap agreements Prior to September 30, 2011, we entered into interest rate swap agreements typically with the intention of qualifying for hedge accounting under ASC 815. However, as of September 30, 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 is being reclassified from accumulated OCI into interest expense on a straight-line basis over the remaining term of each interest rate swap. Interest rate swap agreements We use interest rate swaps to hedge the variable cash flows associated with borrowings made under our repurchase agreements and Federal Home Loan Bank advance facility. 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 funding agreements and cash flows on such liabilities. Our swap agreements are privately negotiated in the over−the−counter ("OTC") market, with swap agreements entered into subsequent to May 2013 subject to central clearing through a registered commodities exchange ("centrally cleared swaps"). We estimate the fair value of our centrally cleared interest rate swaps using the daily settlement price determined by the respective exchange. Centrally cleared swaps are valued by the exchange using a pricing model that references the underlying rates including the overnight index swap rate and LIBOR forward rate to produce the daily settlement price. We estimate the fair value of our "non-centrally cleared" interest rate swaps based on valuations obtained from third-party pricing services and the swap counterparty (collectively, “third-party valuations”). The third-party valuations are model-driven using observable inputs consisting of LIBOR and the forward yield curve. We also consider the creditworthiness of both us and our counterparties and the impact of netting and credit enhancement provisions contained in each derivative agreement, such as collateral postings. All of our "non-centrally cleared" interest rate swaps are subject to bilateral collateral arrangements. Consequently, no credit valuation adjustment was made in determining the fair value of such instruments. 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 our interest rate swaption agreements based on model-driven valuations obtained from third-party pricing services and the swaption counterparty using observable inputs, taking into account 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 MBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific agency MBS 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 we may utilize TBA dollar roll transactions to finance agency MBS 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 MBS securities. U.S. Treasury securities We purchase or 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 the balance sheet 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 Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Components of Investment Securities	The following tables summarize our investments in agency MBS as of September 30, 2015 and December 31, 2014 (dollars in millions): September 30, 2015 Agency MBS Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Fixed rate $ 52,354 $ 653 $ (145 ) $ 52,862 Adjustable rate 535 16 — 551 CMO 1,010 31 — 1,041 Interest-only and principal-only strips 317 48 (2 ) 363 Total agency MBS $ 54,216 $ 748 $ (147 ) $ 54,817 December 31, 2014 Agency MBS Amortized Cost Gross Unrealized Gain Gross Unrealized Loss Fair Value Fixed rate $ 53,945 $ 715 $ (187 ) $ 54,473 Adjustable rate 659 19 — 678 CMO 1,172 24 (1 ) 1,195 Interest-only and principal-only strips 372 33 (3 ) 402 Total agency MBS $ 56,148 $ 791 $ (191 ) $ 56,748
Agency Securities	December 31, 2014 Agency MBS Fannie Mae Freddie Mac Ginnie Mae Total Available-for-sale agency MBS: Agency MBS, par $ 42,749 $ 10,566 $ 107 $ 53,422 Unamortized discount (37 ) (5 ) — (42 ) Unamortized premium 1,880 514 2 2,396 Amortized cost 44,592 11,075 109 55,776 Gross unrealized gains 610 145 3 758 Gross unrealized losses (127 ) (61 ) — (188 ) Total available-for-sale agency MBS, at fair value 45,075 11,159 112 56,346 Agency MBS measured at fair value through earnings: Interest-only and principal-only strips, amortized cost 1 348 24 — 372 Gross unrealized gains 30 3 — 33 Gross unrealized losses (2 ) (1 ) — (3 ) Total agency MBS measured at fair value through earnings 376 26 — 402 Total agency MBS, at fair value $ 45,451 $ 11,185 $ 112 $ 56,748 Weighted average coupon as of December 31, 2014 2 3.63 % 3.70 % 3.52 % 3.65 % Weighted average yield as of December 31, 2014 3 2.75 % 2.73 % 1.87 % 2.74 % ________________________ 1. The underlying UPB of our interest-only agency MBS strips was $1.2 billion and the weighted average contractual interest we are entitled to receive was 5.46% of this amount as of December 31, 2014 . The par value of our principal-only agency MBS strips was $242 million as of December 31, 2014 . 2. The weighted average coupon includes the interest cash flows from our interest-only agency MBS strips taken together with the interest cash flows from our fixed rate, adjustable-rate and CMO agency MBS as a percentage of the par value of our agency MBS (excluding the UPB of our interest-only securities) as of December 31, 2014 . 3. Incorporates a weighted average future constant prepayment rate assumption of 9% based on forward rates as of December 31, 2014 . September 30, 2015 Agency MBS Fannie Mae Freddie Mac Ginnie Mae Total Available-for-sale agency MBS: Agency MBS, par $ 39,898 $ 11,230 $ 559 $ 51,687 Unamortized discount (33 ) (4 ) — (37 ) Unamortized premium 1,718 523 8 2,249 Amortized cost 41,583 11,749 567 53,899 Gross unrealized gains 555 139 6 700 Gross unrealized losses (99 ) (46 ) — (145 ) Total available-for-sale agency MBS, at fair value 42,039 11,842 573 54,454 Agency MBS remeasured at fair value through earnings: Interest-only and principal-only strips, amortized cost 1 297 20 — 317 Gross unrealized gains 43 5 — 48 Gross unrealized losses (1 ) (1 ) — (2 ) Total agency MBS remeasured at fair value through earnings 339 24 — 363 Total agency MBS, at fair value $ 42,378 $ 11,866 $ 573 $ 54,817 Weighted average coupon as of September 30, 2015 2 3.60 % 3.67 % 3.05 % 3.61 % Weighted average yield as of September 30, 2015 3 2.76 % 2.77 % 2.66 % 2.76 % ________________________ 1. The underlying unamortized principal balance ("UPB" or "par value") of our interest-only agency MBS strips was $1.0 billion and the weighted average contractual interest we are entitled to receive was 5.42% of this amount as of September 30, 2015 . The par value of our principal-only agency MBS strips was $216 million as of September 30, 2015 . 2. The weighted average coupon includes the interest cash flows from our interest-only agency MBS strips taken together with the interest cash flows from our fixed rate, adjustable-rate and CMO agency MBS as a percentage of the par value of our agency MBS (excluding the UPB of our interest-only securities) as of September 30, 2015 . 3. Incorporates a weighted average future constant prepayment rate assumption of 9% based on forward rates as of September 30, 2015 .
Summary Of Agency Securities Estimated Weighted Average Life Classifications	The following table summarizes our agency MBS classified as available-for-sale as of September 30, 2015 and December 31, 2014 according to their estimated weighted average life classification (dollars in millions): September 30, 2015 December 31, 2014 Estimated Weighted Average Life of Agency MBS Classified as Available-for-Sale 1 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 $ 322 $ 316 3.67% 2.12% $ 289 $ 280 4.08% 2.62% > 3 years and ≤ 5 years 19,210 18,870 3.28% 2.40% 22,153 21,820 3.26% 2.40% > 5 years and ≤10 years 34,856 34,648 3.65% 2.91% 33,271 33,055 3.73% 2.92% > 10 years 66 65 3.78% 3.37% 633 621 3.28% 3.15% Total $ 54,454 $ 53,899 3.52% 2.72% $ 56,346 $ 55,776 3.54% 2.72% _______________________ 1. Excludes interest and principal-only strips.
Summary of Changes in Accumulated OCI for Agency Securities	changes in accumulated OCI for our available-for-sale securities for the three and nine months ended September 30, 2015 and 2014 .
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 September 30, 2015 and December 31, 2014 (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 September 30, 2015 $ 6,059 $ (30 ) $ 7,298 $ (115 ) $ 13,357 $ (145 ) December 31, 2014 $ 778 $ (2 ) $ 11,679 $ (186 ) $ 12,457 $ (188 )
Summary of Net Gain from Sale of Agency Securities	The following table is a summary of our net gain (loss) from the sale of agency securities classified as available-for-sale for the three and nine months ended September 30, 2015 and 2014 (in millions): Three Months Ended September 30, Nine Months Ended September 30, Agency Securities Classified as Available-for-Sale 2015 2014 2015 2014 Agency MBS sold, at cost $ (4,575 ) $ (8,763 ) $ (22,548 ) $ (25,640 ) Proceeds from agency MBS sold 1 4,536 8,777 22,523 25,657 Net gain (loss) on sale of agency MBS $ (39 ) $ 14 $ (25 ) $ 17 Gross gain on sale of agency MBS $ 2 $ 41 $ 81 $ 132 Gross loss on sale of agency MBS (41 ) (27 ) (106 ) (115 ) Net gain (loss) on sale of agency MBS $ (39 ) $ 14 $ (25 ) $ 17 ________________________ 1. Proceeds include cash received during the period, plus receivable for agency MBS sold during the period as of period end.

Repurchase Agreements and Oth19

Repurchase Agreements and Other Debt (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure of Repurchase Agreements [Abstract]
Schedule of Borrowings under Repurchase Agreements and Weighted Average Interest Rates	The following table summarizes our borrowings under repurchase arrangements and weighted average interest rates classified by remaining maturities as of September 30, 2015 and December 31, 2014 (dollars in millions): September 30, 2015 December 31, 2014 Remaining Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Agency repo: ≤ 1 month $ 17,335 0.45 % 14 $ 14,157 0.37 % 15 > 1 to ≤ 3 months 10,209 0.52 % 59 20,223 0.38 % 61 > 3 to ≤ 6 months 5,167 0.54 % 135 6,654 0.42 % 120 > 6 to ≤ 9 months 1,963 0.59 % 208 1,575 0.50 % 225 > 9 to ≤ 12 months 500 0.64 % 292 2,678 0.54 % 313 > 12 to ≤ 24 months 1,078 0.61 % 634 600 0.57 % 551 > 24 to ≤ 36 months 1,252 0.66 % 812 952 0.60 % 999 > 36 to ≤ 48 months 1,350 0.75 % 1,254 650 0.64 % 1,266 > 48 to < 60 months 1,700 0.73 % 1,560 900 0.68 % 1,542 Total agency repo 40,554 0.52 % 201 48,389 0.41 % 143 U.S. Treasury repo: 1 day 208 0.38 % 1 1,907 0.09 % 1 > 1 day to ≤ 1 month 252 0.30 % 9 — — % — Total U.S. Treasury repo 460 0.34 % 5 1,907 0.09 % 1 Total $ 41,014 0.52 % 199 $ 50,296 0.40 % 138
Schedule of Federal Home Loan Bank Advances and Weighted Average Interest Rates [Table Text Block]	As of September 30, 2015 , OGI had $3.5 billion of outstanding secured FHLB advances, with a weighted average borrowing rate of 0.27% and a weighted average remaining term to maturity of 3.5 years, consisting of 30 day advances and longer-term floating rate advances with a one month cancellation feature: September 30, 2015 Remaining Maturity FHLB Advances Weighted Average Interest Rate Weighted Average Days to Maturity ≤ 1 month $ 753 0.27 % 6 > 9 to ≤ 12 months 245 0.35 % 322 > 36 to ≤ 48 months 411 0.26 % 1,419 > 48 to < 60 months 2,093 0.26 % 1,813 Total FHLB advances $ 3,502 0.27 % 1,274

Derivative and Other Hedging 20

Derivative and Other Hedging Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
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 and liabilities as of September 30, 2015 and December 31, 2014 (in millions): Derivative and Other Hedging Instruments Balance Sheet Location September 30, 2015 December 31, 2014 Interest rate swaps Derivative assets, at fair value $ — $ 136 Swaptions Derivative assets, at fair value 21 75 TBA securities Derivative assets, at fair value 122 197 Total derivative assets, at fair value $ 143 $ 408 Interest rate swaps Derivative liabilities, at fair value $ (1,523 ) $ (880 ) TBA securities Derivative liabilities, at fair value (2 ) (5 ) U.S. Treasury futures - short Derivative liabilities, at fair value (9 ) (5 ) Other Derivative liabilities, at fair value (2 ) — Total derivative liabilities, at fair value $ (1,536 ) $ (890 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ 787 $ 2,427 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (1,309 ) (5,363 ) Total - U.S. Treasury securities, net at fair value $ (522 ) $ (2,936 )
Schedule of Interest Rate Swaption Agreements Outstanding	The following table summarizes our interest rate payer swaption agreements outstanding as of September 30, 2015 and December 31, 2014 (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) September 30, 2015 ≤ 1 year $ 95 $ 21 5 $ 3,650 3.35% 3M 8.2 December 31, 2014 ≤ 1 year $ 113 $ 36 6 $ 5,600 3.15% 3M 6.4 > 1 to ≤ 2 years 32 10 16 1,200 3.87% 3M 5.1 Total Payer Swaptions $ 145 $ 46 8 $ 6,800 3.28% 3M 6.2 The following table summarizes our interest rate receiver swaption agreements outstanding as of December 31, 2014 (dollars in millions). We had no interest rate receiver swaptions outstanding as of September 30, 2015 . Receiver Swaptions Option Underlying Receiver Swap Years to Expiration Cost Fair Value Average Months to Expiration Notional Amount Average Fixed Receive Rate Average Pay Rate (LIBOR) Average Term (Years) December 31, 2014 ≤ 1 year $ 18 $ 29 5 $ 4,250 1.78% 3M 6.4
US government securities	The following table summarizes our U.S. Treasury securities as of September 30, 2015 and December 31, 2014 (in millions): September 30, 2015 December 31, 2014 Maturity Face Amount Net Long / (Short) Cost Basis Market Value Face Amount Net Long / (Short) Cost Basis Market Value 5 years $ 597 $ 604 $ 605 $ (4,674 ) $ (4,650 ) $ (4,645 ) 7 years (90 ) (89 ) (88 ) (717 ) (717 ) (718 ) 10 years (1,033 ) (1,028 ) (1,039 ) 2,410 2,422 2,427 Total U.S. Treasury securities, net $ (526 ) $ (513 ) $ (522 ) $ (2,981 ) $ (2,945 ) $ (2,936 )
Summary of Long and Short Position of Derivative Instruments	The following tables summarize our TBA securities as of September 30, 2015 and December 31, 2014 (in millions): September 30, 2015 December 31, 2014 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% $ (409 ) $ (414 ) $ (417 ) $ (3 ) $ 962 $ 968 $ 980 $ 12 3.0% 143 148 149 1 2,779 2,889 2,888 (1 ) 3.5% 4 4 4 — (468 ) (495 ) (494 ) 1 4.0% — — — — (13 ) (14 ) (14 ) — Total 15-Year TBAs (262 ) (262 ) (264 ) (2 ) 3,260 3,348 3,360 12 30-Year TBA securities: 3.0% 3,441 3,424 3,480 56 5,254 5,259 5,313 54 3.5% 1,873 1,900 1,954 54 7,902 8,151 8,232 81 4.0% 2,076 2,203 2,215 12 (1,853 ) (2,019 ) (1,974 ) 45 4.5% — — — — (151 ) (163 ) (163 ) — Total 30-Year TBAs 7,390 7,527 7,649 122 11,152 11,228 11,408 180 Total net TBA securities $ 7,128 $ 7,265 $ 7,385 $ 120 $ 14,412 $ 14,576 $ 14,768 $ 192 September 30, 2015 December 31, 2014 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 $ 6,572 $ 6,698 $ 6,807 $ 109 $ 15,127 $ 15,316 $ 15,509 $ 193 Freddie Mac 256 255 264 9 (715 ) (740 ) (741 ) (1 ) Ginnie Mae 300 312 314 2 — — — — TBA securities, net $ 7,128 $ 7,265 $ 7,385 $ 120 $ 14,412 $ 14,576 $ 14,768 $ 192 _____________________ 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 and nine months ended September 30, 2015 and 2014 (in millions): Three Months Ended September 30, 2015 Derivative and Other Hedging Instruments Notional Amount Long/(Short) June 30, 2015 Additions Settlement, Termination, Expiration or Exercise Notional Amount Long/(Short) September 30, 2015 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 6,941 33,403 (33,216 ) $ 7,128 $ 213 Interest rate swaps $ (44,925 ) (1,450 ) 1,200 $ (45,175 ) (966 ) Payer swaptions $ (5,450 ) — 1,800 $ (3,650 ) (23 ) U.S. Treasury securities - short position $ (2,250 ) (4,335 ) 5,284 $ (1,301 ) (25 ) U.S. Treasury securities - long position $ 5,192 4,704 (9,121 ) $ 775 29 U.S. Treasury futures contracts - short position $ (730 ) (730 ) 730 $ (730 ) (23 ) $ (795 ) ________________________________ 1. Excludes a net gain of $7 million from debt of consolidated VIEs and a net gain of $10 million from interest and principal-only securities recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Three Months Ended September 30, 2014 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount Long/(Short) September 30, 2014 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 17,811 44,438 (44,990 ) $ 17,259 $ 33 Interest rate swaps $ (47,900 ) (3,625 ) 11,300 $ (40,225 ) (26 ) Payer swaptions $ (7,650 ) (1,500 ) 3,000 $ (6,150 ) (14 ) Receiver swaptions $ 1,750 750 — $ 2,500 — U.S. Treasury securities - short position $ (5,988 ) (5,974 ) 7,263 $ (4,699 ) (44 ) U.S. Treasury securities - long position $ 1,250 5,028 (5,055 ) $ 1,223 (8 ) U.S. Treasury futures contracts - short position $ (730 ) (730 ) 730 $ (730 ) — TBA put option $ (100 ) — 100 $ — — $ (59 ) ______________________ 1. Excludes a net loss of $2 million from investments in REIT equity securities, a net gain of $6 million from debt of consolidated VIEs and a net gain of $4 million from interest and principal-only securities recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Nine Months Ended September 30, 2015 Derivative and Other Hedging Instruments Notional Amount Long/(Short) December 31, 2014 Additions Settlement, Termination, Expiration or Exercise Notional Amount Long/(Short) September 30, 2015 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 14,412 97,270 (104,554 ) $ 7,128 $ 337 Interest rate swaps $ (43,700 ) (4,950 ) 3,475 $ (45,175 ) (1,278 ) Payer swaptions $ (6,800 ) (500 ) 3,650 $ (3,650 ) (27 ) Receiver swaptions $ 4,250 — (4,250 ) $ — 4 U.S. Treasury securities - short position $ (5,392 ) (10,732 ) 14,823 $ (1,301 ) (89 ) U.S. Treasury securities - long position $ 2,411 31,915 (33,551 ) $ 775 (35 ) U.S. Treasury futures contracts - short position $ (730 ) (2,190 ) 2,190 $ (730 ) (28 ) $ (1,116 ) ________________________________ 1. Excludes a net gain of $16 million from debt of consolidated VIEs, a net gain of $14 million from interest and principal-only securities and other miscellaneous net losses of $4 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Nine Months Ended September 30, 2014 Derivative and Other Hedging Instruments Notional Amount Additions Settlement, Termination, Expiration or Exercise Notional Amount Long/(Short) September 30, 2014 Amount of Gain/(Loss) Recognized in Income on Derivatives 1 TBA securities, net $ 2,119 134,760 (119,620 ) $ 17,259 $ 637 Interest rate swaps $ (43,250 ) (12,325 ) 15,350 $ (40,225 ) (993 ) Payer swaptions $ (14,250 ) (3,750 ) 11,850 $ (6,150 ) (160 ) Receiver swaptions $ — 2,500 — $ 2,500 — U.S. Treasury securities - short position $ (2,007 ) (21,830 ) 19,138 $ (4,699 ) (262 ) U.S. Treasury securities - long position $ 3,927 9,963 (12,667 ) $ 1,223 72 U.S. Treasury futures contracts - short position $ (1,730 ) (2,190 ) 3,190 $ (730 ) (55 ) TBA put option $ — (150 ) 150 $ — — $ (761 ) ______________________ 1. Excludes a net gain of $71 million from investments in REIT equity securities, a net loss of $6 million from debt of consolidated VIEs, a net gain of $31 million from interest and principal-only securities and other miscellaneous net losses of $7 million recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income.
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Schedule Of Interest Rate Swap Agreement By Remaining Maturity	The following tables summarize our interest rate swap agreements outstanding as of September 30, 2015 and December 31, 2014 (dollars in millions): September 30, 2015 Payer Interest Rate Swaps Notional Amount 1 Average Fixed Pay Rate 2 Average Receive Rate 3 Net Estimated Fair Value Average Maturity (Years) ≤ 3 years $ 16,725 1.21% 0.29% $ (133 ) 1.6 > 3 to ≤ 5 years 9,450 1.93% 0.32% (277 ) 4.1 > 5 to ≤ 7 years 8,425 2.43% 0.32% (373 ) 6.2 > 7 to ≤ 10 years 9,050 2.67% 0.31% (588 ) 8.2 > 10 years 1,525 3.21% 0.32% (152 ) 13.9 Total Payer Interest Rate Swaps $ 45,175 1.95% 0.30% $ (1,523 ) 4.7 ________________________ 1. Notional amount includes forward starting swaps of $7.8 billion with an average forward start date of 0.6 years and an average maturity of 6.3 years from September 30, 2015 . 2. Average fixed pay rate includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.72% as of September 30, 2015 . 3. Average receive rate excludes forward starting swaps. December 31, 2014 Payer Interest Rate Swaps Notional 1 Average 2 Average 3 Net Average ≤ 3 years $ 12,300 1.33% 0.21% $ (87 ) 2.0 > 3 to ≤ 5 years 8,975 1.63% 0.24% (4 ) 4.2 > 5 to ≤ 7 years 7,250 2.47% 0.23% (139 ) 6.1 > 7 to ≤ 10 years 10,775 2.48% 0.24% (223 ) 8.3 > 10 years 4,400 3.19% 0.23% (291 ) 12.6 Total Payer Interest Rate Swaps $ 43,700 2.05% 0.23% $ (744 ) 5.8 ________________________ 1. Notional amount includes forward starting swaps of $12.4 billion with an average forward start date of 1.1 years and an average maturity of 7.9 years from December 31, 2014 . 2. Average fixed pay rate includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.68% as of December 31, 2014 . 3. Average receive rate excludes forward starting swaps.

Pledged Assets (Tables)

Pledged Assets (Tables)	9 Months Ended
	Sep. 30, 2015
Pledged Assets [Abstract]
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Table Text Block]	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 September 30, 2015 (dollars in millions). As of December 31, 2014 , the maximum amount at risk with any counterparty related to our repurchase agreements was less than 5% of our stockholders' equity. September 30, 2015 Amount Outstanding Net Counterparty Exposure 1 Percent of Equity Weighted Average Days to Maturity J.P. Morgan Securities, LLC $ 4,585 $ 496 6 % 1,076
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 September 30, 2015 and December 31, 2014 (in millions): September 30, 2015 Assets Pledged to Counterparties Repurchase Agreements and FHLB Advances 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements Total Agency MBS - fair value $ 46,798 $ 1,088 $ 247 $ 531 $ 48,664 U.S. Treasury securities - fair value 462 — 452 — 914 Accrued interest on pledged securities 130 3 2 2 137 Restricted cash 26 — 1,356 31 1,413 Total $ 47,416 $ 1,091 $ 2,057 $ 564 $ 51,128 ______________________ 1. Includes $256 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements. December 31, 2014 Assets Pledged to Counterparties Repurchase Agreements 1 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements Total Agency MBS - fair value $ 51,037 $ 1,266 $ 69 $ 702 $ 53,074 U.S. Treasury securities - fair value 1,904 — 550 — 2,454 Accrued interest on pledged securities 147 4 2 — 153 Restricted cash 6 — 698 9 713 Total $ 53,094 $ 1,270 $ 1,319 $ 711 $ 56,394 ______________________ 1. Includes $179 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements.
Schedules Of Securities Pledged As Collateral Under Repurchase Agreement	The following table summarizes our securities pledged as collateral under our repurchase agreements and FHLB advances by the remaining maturity of our borrowings, including securities pledged related to sold but not yet settled securities, as of September 30, 2015 and December 31, 2014 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 5 . September 30, 2015 December 31, 2014 Agency 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 Agency MBS: 1 ≤ 30 days $ 18,800 $ 18,548 $ 51 $ 14,659 $ 14,509 $ 41 > 30 and ≤ 60 days 5,626 5,582 16 10,906 10,784 30 > 60 and ≤ 90 days 4,820 4,774 13 10,205 10,109 28 > 90 days 17,552 17,375 49 15,267 15,096 43 Total agency MBS 46,798 46,279 129 51,037 50,498 142 U.S. Treasury securities: 1 day 209 207 — 1,904 1,899 5 > 1 day ≤ 30 days 253 253 1 — — — Total U.S. Treasury securities 462 460 1 1,904 1,899 5 Total $ 47,260 $ 46,739 $ 130 $ 52,941 $ 52,397 $ 147
Schedule of Securities and Cash Pledged as Collateral from Counterparties	As of September 30, 2015 and December 31, 2014 , we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions). September 30, 2015 December 31, 2014 Assets Pledged to AGNC Reverse Repurchase Agreements Derivative Agreements Total Reverse Repurchase Agreements Derivative Agreements Total Agency MBS - fair value $ — $ — $ — $ — $ 43 $ 43 U.S. Treasury securities - fair value 1,309 — 1,309 5,363 47 5,410 Cash — — — — 28 28 Total $ 1,309 $ — $ 1,309 $ 5,363 $ 118 $ 5,481
Offsetting Assets and Liabilities	The following tables present information about our assets and liabilities that are subject to such arrangements and can potentially be offset on our consolidated balance sheets as of September 30, 2015 and December 31, 2014 (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 September 30, 2015 Interest rate swap and swaption agreements, at fair value 1 $ 21 $ — $ 21 $ (21 ) $ — $ — Receivable under reverse repurchase agreements 1,463 — 1,463 (1,459 ) (4 ) — Total $ 1,484 $ — $ 1,484 $ (1,480 ) $ (4 ) $ — December 31, 2014 Interest rate swap and swaption agreements, at fair value 1 $ 211 $ — $ 211 $ (94 ) $ (83 ) $ 34 Receivable under reverse repurchase agreements 5,218 — 5,218 (4,690 ) (528 ) — Total $ 5,429 $ — $ 5,429 $ (4,784 ) $ (611 ) $ 34
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 September 30, 2015 Interest rate swap agreements, at fair value 1 $ 1,523 $ — $ 1,523 $ (21 ) $ (1,502 ) $ — Repurchase agreements and FHLB advances 44,516 — 44,516 (1,459 ) (43,057 ) — Total $ 46,039 $ — $ 46,039 $ (1,480 ) $ (44,559 ) $ — December 31, 2014 Interest rate swap agreements, at fair value 1 $ 880 $ — $ 880 $ (94 ) $ (782 ) $ 4 Repurchase agreements 50,296 — 50,296 (4,690 ) (45,606 ) — Total $ 51,176 $ — $ 51,176 $ (4,784 ) $ (46,388 ) $ 4 _______________________ 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)	9 Months Ended
	Sep. 30, 2015
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 September 30, 2015 and December 31, 2014 (in millions): September 30, 2015 December 31, 2014 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 53,729 $ — $ — $ 55,482 $ — Agency securities transferred to consolidated VIEs — 1,088 — — 1,266 — U.S. Treasury securities 787 — — 2,427 — — Interest rate swaps — — — — 136 — Swaptions — 21 — — 75 — REIT equity securities 34 — — 68 — — TBA securities — 122 — — 197 — Total $ 821 $ 54,960 $ — $ 2,495 $ 57,156 $ — Liabilities: Debt of consolidated VIEs $ — $ 626 $ — $ — $ 761 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 1,309 — — 5,363 — — Interest rate swaps — 1,523 — — 880 — TBA securities — 2 — — 5 — U.S. Treasury futures 9 — — 5 — — Other — 2 — — — — Total $ 1,318 $ 2,153 $ — $ 5,368 $ 1,646 $ —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes changes to accumulated OCI for the three and nine months ended September 30, 2015 and 2014 (in millions): Accumulated Other Comprehensive Income (Loss) Net Unrealized Gain (Loss) on Available-for-Sale MBS Net Unrealized Gain (Loss) on Swaps Total Accumulated OCI Balance Three Months Ended September 30, 2015 Balance as of June 30, 2015 $ 89 $ (85 ) $ 4 OCI before reclassifications 428 — 428 Amounts reclassified from accumulated OCI 39 24 63 Balance as of September 30, 2015 $ 556 $ (61 ) $ 495 Three Months Ended September 30, 2014 Balance as of June 30, 2014 $ 225 $ (213 ) $ 12 OCI before reclassifications (239 ) — (239 ) Amounts reclassified from accumulated OCI (14 ) 38 24 Balance as of September 30, 2014 $ (28 ) $ (175 ) $ (203 ) Nine Months Ended September 30, 2015 Balance as of December 31, 2014 $ 570 $ (140 ) $ 430 OCI before reclassifications (39 ) — (39 ) Amounts reclassified from accumulated OCI 25 79 104 Balance as of September 30, 2015 $ 556 $ (61 ) $ 495 Nine Months Ended September 30, 2014 Balance as of December 31, 2013 $ (1,087 ) $ (296 ) $ (1,383 ) OCI before reclassifications 1,076 — 1,076 Amounts reclassified from accumulated OCI (17 ) 121 104 Balance as of September 30, 2014 $ (28 ) $ (175 ) $ (203 ) The following table summarizes reclassifications out of accumulated OCI for the three and nine months ended September 30, 2015 and 2014 (in millions): Three Months Ended September 30, Nine Months Ended September 30, Line Item in the Consolidated Statements of Comprehensive Income Where Net Income is Presented Amounts Reclassified from Accumulated OCI 2015 2014 2015 2014 (Gain) loss amounts reclassified from accumulated OCI for available-for-sale MBS upon realization $ 39 $ (14 ) $ 25 $ (17 ) Gain (loss) on sale of agency securities, net Periodic interest costs of interest rate swaps previously designated as hedges under GAAP, net 24 38 79 121 Interest expense Total reclassifications $ 63 $ 24 $ 104 $ 104

Organization (Details)

Organization (Details)	9 Months Ended
	Sep. 30, 2015
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 Accoun25

Summary of Significant Accounting Policies (Details)	9 Months Ended
	Sep. 30, 2015
Maximum [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Term of derivative contract	20 years

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Total agency MBS, at fair value	$ 54,817		$ 54,817		$ 56,748
Weighted average expected constant prepayment rate			9.00%		9.00%
Weighted average life of interest-only strips			5 years 10 months 25 days		6 years 17 days
Weighted average life of principal-only strips			7 years 9 months 16 days		8 years 28 days
Agency securities, total fair value	1,100		$ 1,100		$ 1,300
Debt, at fair value	626		626		761
Principal balance of agency securities collaterizing debt issued by securitization trust	(1,000)		(1,000)		1,200
Principal amount	621		621		742
Gain (loss) associated with consolidated debt	7	$ 6	16	$ (6)
Fair value of CMO securities and interest-only and principal-only strips	1,400		1,400		1,600
Securitized CMO Securities	1,900		1,900		2,100
CMO and Interest Only, Principal Only Securities, Maximum Loss Exposure			267		274
Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unamortized premium balance	2,300		2,300		2,500
Interest Only And Principal Only Strip [Member]
Schedule of Available-for-sale Securities [Line Items]
Net unrealized gain	10	$ 4	14	$ 31
TBA securities Fifteen Year and Thirty Year Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Net long TBA position, at fair value	7,400		7,400		14,800
TBA, net carrying value	$ 120		$ 120		$ 192

Investment Securities (Summary

Investment Securities (Summary of Investment in Agency Security) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Amortized cost	$ 53,899	$ 55,776
Gross unrealized gain	748	791
Gross unrealized loss	(147)	(191)
Fair value	54,454	56,346
Total agency MBS, amortized cost	54,216	56,148
Total agency MBS, at fair value	54,817	56,748
Fixed Income Securities [Member]
Gross unrealized gain	653	715
Gross unrealized loss	(145)	187
Fixed Income Securities [Member] | Agency Securities [Member]
Amortized cost	52,354	53,945
Fair value	52,862	54,473
Adjustable-Rate [Member]
Gross unrealized gain	16	19
Gross unrealized loss	0	0
Adjustable-Rate [Member] | Agency Securities [Member]
Amortized cost	535	659
Fair value	551	678
Collateralized Mortgage Obligations [Member]
Gross unrealized gain	31	24
Gross unrealized loss	0	1
Collateralized Mortgage Obligations [Member] | Agency Securities [Member]
Amortized cost	1,010	1,172
Fair value	1,041	1,195
Interest Only And Principal Only Strip [Member]
Gross unrealized gain	48	33
Gross unrealized loss	(2)	3
Interest Only And Principal Only Strip [Member] | Agency Securities [Member]
Interest-only and principal-only strips, amortized cost	317	372
Interest-only and principal-only strips, fair value	$ 363	$ 402

Investment Securities (Componen

Investment Securities (Components Of Investment Securities) (Details) - USD ($) $ in Millions		9 Months Ended	12 Months Ended
		Sep. 30, 2015	Dec. 31, 2014
Schedule of Investments [Line Items]
Amortized cost		$ 53,899	$ 55,776
Total agency MBS, at fair value		$ 54,817	$ 56,748
Weighted average coupon		3.61%	3.65%	[1]
Weighted average yield		2.76%	2.74%	[2]
Unamortized Principal Balance Of Interest Only Strips		$ 1,000	$ 1,200
Weighted Average Contractual Interest Rate Of Interest Only Strips		5.42%	5.46%
Unamortized Principal Balance Of Principal Only Strips		$ 216	$ 242
Future Prepayment Rate Assumption Of Investment Portfolio		9.00%	9.00%
Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Agency MBS, par		$ 51,687	$ 53,422
Unamortized discount		(37)	(42)
Unamortized premium		2,249	2,396
Amortized cost		53,899	55,776
Gross unrealized gains		700	758
Gross unrealized losses		(145)	(188)
Total available-for-sale agency MBS, at fair value		54,454	56,346
Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Interest-only and principal-only strips, amortized cost		317	372
Gross unrealized gains		48	33
Gross unrealized losses		(2)	(3)
Total agency MBS measured at fair value through earnings		363	402
Fannie Mae [Member]
Schedule of Investments [Line Items]
Total agency MBS, at fair value		$ 42,378	$ 45,451
Weighted average coupon	[1]	3.60%	3.63%
Weighted average yield	[2]	2.76%	2.75%
Fannie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Agency MBS, par		$ 39,898	$ 42,749
Unamortized discount		(33)	(37)
Unamortized premium		1,718	1,880
Amortized cost		41,583	44,592
Gross unrealized gains		555	610
Gross unrealized losses		(99)	(127)
Total available-for-sale agency MBS, at fair value		42,039	45,075
Fannie Mae [Member] | Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Interest-only and principal-only strips, amortized cost		297	348
Gross unrealized gains		43	30
Gross unrealized losses		(1)	(2)
Total agency MBS measured at fair value through earnings		339	376
Freddie Mac [Member]
Schedule of Investments [Line Items]
Total agency MBS, at fair value		$ 11,866	$ 11,185
Weighted average coupon	[1]	3.67%	3.70%
Weighted average yield	[2]	2.77%	2.73%
Freddie Mac [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Agency MBS, par		$ 11,230	$ 10,566
Unamortized discount		(4)	(5)
Unamortized premium		523	514
Amortized cost		11,749	11,075
Gross unrealized gains		139	145
Gross unrealized losses		(46)	(61)
Total available-for-sale agency MBS, at fair value		11,842	11,159
Freddie Mac [Member] | Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Interest-only and principal-only strips, amortized cost		20	24
Gross unrealized gains		5	3
Gross unrealized losses		(1)	(1)
Total agency MBS measured at fair value through earnings		24	26
Ginnie Mae [Member]
Schedule of Investments [Line Items]
Total agency MBS, at fair value		$ 573	$ 112
Weighted average coupon	[1]	3.05%	3.52%
Weighted average yield	[2]	2.66%	1.87%
Ginnie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Agency MBS, par		$ 559	$ 107
Unamortized discount		0	0
Unamortized premium		8	2
Amortized cost		567	109
Gross unrealized gains		6	3
Gross unrealized losses		0	0
Total available-for-sale agency MBS, at fair value		573	112
Ginnie Mae [Member] | Agency securities remeasured at fair value through earnings [Member]
Schedule of Investments [Line Items]
Interest-only and principal-only strips, amortized cost		0	0
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total agency MBS measured at fair value through earnings		$ 0	$ 0
[1]	The underlying unamortized principal balance ("UPB" or "par value") of our interest-only agency MBS strips was $1.0 billion and the weighted average contractual interest we are entitled to receive was 5.42% of this amount as of September 30, 2015. The par value of our principal-only agency MBS strips was $216 million as of September 30, 2015.
[2]	Incorporates a weighted average future constant prepayment rate assumption of 9% based on forward rates as of September 30, 2015

Investment Securities (Summar29

Investment Securities (Summary Of Agency Securities Estimated Weighted Average Life Classifications) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Agency securities classified as available for sale, Fair value	$ 54,454	$ 56,346
Agency securities classified as available for sale, Amortized cost	$ 53,899	$ 55,776
Weighted Average Coupon	3.52%	3.54%
Weighted Average Yield	2.72%	2.72%
Greater Than One Year and Less Than or Equal to Three Years [Member]
Fair Value	$ 322	$ 289
Amortized Cost	$ 316	$ 280
Weighted Average Coupon	3.67%	4.08%
Weighted Average Yield	2.12%	2.62%
Greater Than Three Years and Less Than or Equal to Five Years [Member]
Fair Value	$ 19,210	$ 22,153
Amortized Cost	$ 18,870	$ 21,820
Weighted Average Coupon	3.28%	3.26%
Weighted Average Yield	2.40%	2.40%
Greater Than Five Years [Member]
Fair Value	$ 34,856	$ 33,271
Amortized Cost	$ 34,648	$ 33,055
Weighted Average Coupon	3.65%	3.73%
Weighted Average Yield	2.91%	2.92%
Greater Than Ten Years [Member]
Fair Value	$ 66	$ 633
Amortized Cost	$ 65	$ 621
Weighted Average Coupon	3.78%	3.28%
Weighted Average Yield	3.37%	3.15%

Investment Securities (Summar30

Investment Securities (Summary Of Changes In Accumulated OCI For Available-For-Sale Security) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Unrealized Gains and (Losses), Net	$ 467	$ (253)	$ (14)	$ 1,059
Agency Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning OCI Balance	89	225	570	(1,087)
Unrealized Gains and (Losses), Net	428	(239)	(39)	1,076
Reversal of Unrealized (Gains) and Losses, Net on Realization	39	(14)	25	(17)
Ending OCI Balance	$ 556	$ (28)	$ 556	$ (28)

Investment Securities (Summar31

Investment Securities (Summary Of Continuous Unrealized Loss Positions Of Available-For-Sale Security) (Details) - Accumulated Other Comprehensive Income (Loss) [Member] - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Unrealized Loss Position For - Estimated Fair Value - Less than 12 Months	$ 6,059	$ 778
Unrealized Loss Position For - Unrealized Loss - Less than 12 Months	(30)	(2)
Unrealized Loss Position For - Estimated Fair Value - 12 Months or More	7,298	11,679
Unrealized Loss Position For - Unrealized Loss - 12 Months or More	(115)	(186)
Unrealized Loss Position For - Estimated Fair Value - Total	13,357	12,457
Unrealized Loss Position For - Unrealized Loss - Total	$ (145)	$ (188)

Investment Securities (Summar32

Investment Securities (Summary Of Net Gain From Sale Of Agency Securities) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Proceeds from agency MBS sold			$ 44,237	$ 34,203
Net gain (loss) on sale of agency MBS	$ (39)	$ 14	(25)	17
Agency Securities [Member]
Agency MBS sold, at cost	(4,575)	(8,763)	(22,548)	(25,640)
Proceeds from agency MBS sold	4,536	8,777	22,523	25,657
Net gain (loss) on sale of agency MBS	(39)	14	(25)	17
Gross gain on sale of agency MBS	2	41	81	132
Gross loss on sale of agency MBS	(41)	(27)	(106)	(115)
Interest Only And Principal Only Strip [Member]
Unrealized Gain (Loss) on Securities	$ 10	$ 4	$ 14	$ 31

Repurchase Agreements And Oth33

Repurchase Agreements And Other Debt (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Assets Sold under Agreements to Repurchase [Line Items]
Debt of consolidated variable interest entities, at fair value	$ 626	$ 761
Description of variable rate basis	LIBOR
Basis spread over LIBOR	40	43
Principal amount	$ 621	$ 742
Weighted average life of other debt	4 years 6 months 20 days	5 years 9 months
TBA and Forward Settling Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Forward Settlement Value	$ 7,265	$ 14,576
Derivative, Fair Value, Net	120	192
TBA securities Fifteen Year and Thirty Year Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Fair Value, Net	$ 120	$ 192

Repurchase Agreements And Oth34

Repurchase Agreements And Other Debt (Repurchase Arrangements And Weighted Average Interest Rates Classified By Original Maturities) (Details) $ in Millions	Sep. 30, 2015USD ($)days	Dec. 31, 2014USD ($)days
Repurchase Agreements	$ 41,014	$ 50,296
Weighted Average Days to Maturity | days	199	138
30 Days or Less [Member]
Repurchase Agreements	$ 17,335	$ 14,157
Weighted Average Interest Rate	0.45%	0.37%
Weighted Average Days to Maturity | days	14	15
1 to 3 Months
Repurchase Agreements	$ 10,209	$ 20,223
Weighted Average Interest Rate	0.52%	0.38%
Weighted Average Days to Maturity | days	59	61
3 to 6 Months
Repurchase Agreements	$ 5,167	$ 6,654
Weighted Average Interest Rate	0.54%	0.42%
Weighted Average Days to Maturity | days	135	120
6 to 9 Months
Repurchase Agreements	$ 1,963	$ 1,575
Weighted Average Interest Rate	0.59%	0.50%
Weighted Average Days to Maturity | days	208	225
9 to 12 Months
Repurchase Agreements	$ 500	$ 2,678
Weighted Average Interest Rate	0.64%	0.54%
Weighted Average Days to Maturity | days	292	313
12 to 24 Months
Repurchase Agreements	$ 1,078	$ 600
Weighted Average Interest Rate	0.61%	0.57%
Weighted Average Days to Maturity | days	634	551
24 to 36 Months
Repurchase Agreements	$ 1,252	$ 952
Weighted Average Interest Rate	0.66%	0.60%
Weighted Average Days to Maturity | days	812	999
36 to 48 months
Repurchase Agreements	$ 1,350	$ 650
Weighted Average Interest Rate	0.75%	0.64%
Weighted Average Days to Maturity | days	1,254	1,266
48 to 60 Months
Repurchase Agreements	$ 1,700	$ 900
Weighted Average Interest Rate	0.73%	0.68%
Weighted Average Days to Maturity | days	1,560	1,542
Maturity Overnight [Member]
Repurchase Agreements	$ 208	$ 1,907
Weighted Average Interest Rate	0.38%	0.09%
Weighted Average Days to Maturity | days	1	1
2 Days to 1 Month [Member]
Repurchase Agreements	$ 252	$ 0
Weighted Average Interest Rate	0.30%	0.00%
Weighted Average Days to Maturity | days	9	0
Repurchase Agreements [Member]
Weighted Average Interest Rate	0.52%	0.40%
Agency Securities [Member]
Repurchase Agreements	$ 40,554	$ 48,389
Weighted Average Days to Maturity | days	201	143
Agency Securities [Member] | Repurchase Agreements [Member]
Weighted Average Interest Rate	0.52%	0.41%
US Treasury Securities [Member]
Repurchase Agreements	$ 460	$ 1,907
Weighted Average Interest Rate	0.34%	0.09%
Weighted Average Days to Maturity | days	5	1

Repurchase Agreements And Oth35

Repurchase Agreements And Other Debt Federal Home Loan Bank Advances and Weighted Average Interest Rates (Details) $ in Millions	Sep. 30, 2015USD ($)daysyears
Short-term Debt [Line Items]
Short-term Debt, Fair Value	$ 3,502
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.27%
FHLB Weighted Average Days to Maturity | days	1,274
FHLB Weighted Average Years to Maturity | years	3.5
49 to 60 Months [Member]
Short-term Debt [Line Items]
Short-term Debt, Fair Value	$ 2,093
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.26%
FHLB Weighted Average Days to Maturity | days	1,813
37 to 48 months [Member]
Short-term Debt [Line Items]
Short-term Debt, Fair Value	$ 411
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.26%
FHLB Weighted Average Days to Maturity | days	1,419
Maturity Less than 30 Days [Member]
Short-term Debt [Line Items]
Short-term Debt, Fair Value	$ 753
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.27%
FHLB Weighted Average Days to Maturity | days	6
10 to 12 Months [Member]
Short-term Debt [Line Items]
Short-term Debt, Fair Value	$ 245
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.35%
FHLB Weighted Average Days to Maturity | days	322

Derivative and Other Hedging 36

Derivative and Other Hedging Instruments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2013
Unrealized gain on derivative instruments, net	$ 24	$ 38	$ 79	$ 121
Net periodic interest costs on swaps	131	120	369	373
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	107	82	290	252
Discontinuation of Election to Account for Interest Rate Swaps as Designated Cash Flow Hedges [Member]
Net Unrealized Gain (Loss) on Swaps	61	(175)	61	(175)	$ 140	$ 85	$ 213	$ 296
Deferred loss expected to be reclassified from OCI into interest expense over the next twelve months			$ 58
Discontinuation of Election to Account for Interest Rate Swaps as Designated Cash Flow Hedges [Member] | Interest Rate Swaps [Member]
Average Maturity (Years)			9 months 14 days
Interest Only And Principal Only Strip [Member]
Unrealized Gain (Loss) on Securities	$ 10	$ 4	$ 14	$ 31
Forward Contracts [Member] | Interest Rate Swap [Member]
Average Maturity (Years)			6 years 3 months 10 days		7 years 11 months 3 days

Derivative and Other Hedging 37

Derivative and Other Hedging Instruments (Fair Value Information) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Derivative [Line Items]
Derivative asset, fair value	$ 143		$ 143			$ 408
Derivative liability, fair value	(1,536)		(1,536)			(890)
Derivative assets, at fair value	143		143			408
U.S. Treasury securities	787		787			2,427
U.S. Treasury Securities - short	(1,309)		(1,309)			(5,363)
Total - (short)/long, net	(522)		(522)			(2,936)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(795)	$ (59)	(1,116)	$ (761)
Put Option [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount		0		0			$ (100)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period		0		(150)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		100		150
Other Assets [Member]
Derivative [Line Items]
Derivative liability, fair value	(2)		(2)
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	7,128	17,259	7,128	17,259	$ 6,941	14,412	17,811	$ 2,119
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	33,403	44,438	97,270	134,760
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period				(119,620)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	213	33	337	637
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	45,175		45,175			43,700
Derivative liability, fair value	(1,523)		(1,523)			(880)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	(1,450)	(3,625)	(4,950)	(12,325)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	1,200	11,300	3,475	15,350
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(966)	(26)	(1,278)	(993)
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	0		0			136
Interest Rate Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount						6,800
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	0	(1,500)	(500)	(3,750)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	1,800	3,000	3,650	11,850
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(23)	(14)	(27)	(160)
Interest Rate Swaption [Member] | Receiver Swaption [Member]
Derivative [Line Items]
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period		750	0	2,500
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		0	(4,250)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		0	4
Interest Rate Swaption [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	21		21			75
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative liability, fair value	(2)		(2)			(5)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(33,216)	(44,990)	(104,554)
Future [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative liability, fair value	(9)		(9)			(5)
US Treasury Securities [Member] | Future [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	(730)	(730)	(730)	(730)	(730)	(730)	(730)	(1,730)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	(730)	(730)	(2,190)	(2,190)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	730	730	2,190	3,190
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(23)	0	(28)	(55)
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	122		122			197
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	(45,175)	(40,225)	(45,175)	(40,225)	(44,925)	(43,700)	(47,900)	(43,250)
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	(3,650)	(6,150)	(3,650)	(6,150)	(5,450)	(6,800)	(7,650)	(14,250)
Not Designated as Hedging Instrument [Member] | Receiver Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	0	2,500	0	2,500		4,250	1,750
Short [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	(1,301)	(4,699)	(1,301)	(4,699)	(2,250)	(5,392)	(5,988)	(2,007)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	(4,335)	(5,974)	(10,732)	(21,830)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	5,284	7,263	14,823	19,138
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(25)	(44)	(89)	(262)
Long [Member]
Derivative [Line Items]
Trading Securities	775	1,223	775	1,223
Long [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	29	(8)	(35)	72
Trading Securities		1,223		1,223	$ 5,192	$ 2,411	$ 1,250	$ 3,927
Trading Securities Added During the Period	4,704	5,028	31,915	9,963
Notional Amount Of Trading Securities Settlement Expiration During The Period	$ (9,121)	$ (5,055)	$ (33,551)	$ (12,667)

Derivative and Other Hedging 38

Derivative and Other Hedging Instruments (Summary Of Outstanding Interest Rate Swaps) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Interest Rate Swap [Member]
Notional Amount	$ 45,175	$ 43,700
Average Fixed Pay Rate	1.95%	2.05%
Average Receive Rate	0.30%	0.23%
Net Estimated Fair Value	$ (1,523)	$ (744)
Average Maturity (Years)	4 years 8 months 22 days	5 years 9 months 1 day
Forward Contracts [Member] | Interest Rate Swap [Member]
Average Maturity (Years)	6 years 3 months 10 days	7 years 11 months 3 days
Derivative, Notional Amount	$ 7,800	$ 12,400
Derivative, Higher Remaining Maturity Range	7 months 23 days	1 year 20 days
Interest Rate Swaps Excluding Forward Starting [Member] | Interest Rate Swap [Member]
Average Fixed Pay Rate	1.72%	1.68%
Greater Than One Year and Less Than or Equal to Three Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 16,725	$ 12,300
Average Fixed Pay Rate	1.21%	1.33%
Average Receive Rate	0.29%	0.21%
Net Estimated Fair Value	$ (133)	$ (87)
Average Maturity (Years)	1 year 7 months 15 days	2 years 6 days
Greater Than Three Years and Less Than or Equal to Five Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 9,450	$ 8,975
Average Fixed Pay Rate	1.93%	1.63%
Average Receive Rate	0.32%	0.24%
Net Estimated Fair Value	$ (277)	$ (4)
Average Maturity (Years)	4 years 30 days	4 years 2 months 7 days
Greater Than Five Years and Less than or Equal to Seven Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 8,425	$ 7,250
Average Fixed Pay Rate	2.43%	2.47%
Average Receive Rate	0.32%	0.23%
Net Estimated Fair Value	$ (373)	$ (139)
Average Maturity (Years)	6 years 2 months 21 days	6 years 24 days
Greater Than Seven Years and Less than or Equal to Ten Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 9,050	$ 10,775
Average Fixed Pay Rate	2.67%	2.48%
Average Receive Rate	0.31%	0.24%
Net Estimated Fair Value	$ (588)	$ (223)
Average Maturity (Years)	8 years 2 months 10 days	8 years 3 months 19 days
Greater Than Ten Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 1,525	$ 4,400
Average Fixed Pay Rate	3.21%	3.19%
Average Receive Rate	0.32%	0.23%
Net Estimated Fair Value	$ (152)	$ (291)
Average Maturity (Years)	13 years 10 months 20 days	12 years 7 months 14 days

Derivative and Other Hedging 39

Derivative and Other Hedging Instruments (Remaining Interest Rate Swap Term) (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015USD ($)month	Dec. 31, 2014USD ($)month
Interest Rate Swaption [Member]
Cost		$ 145
Fair Value		$ 46
Average Months to Expiration | month		8
Derivative Liability, Notional Amount		$ 6,800
Average Fixed Pay Rate		3.28%
Average Maturity (Years)		6 years 1 month 29 days
Payer Swaption [Member]
Average Receive Rate (LIBOR)		3M
Less Than or Equal to One Year [Member] | Interest Rate Swaption [Member]
Cost	$ 95	$ 113
Fair Value	$ 21	$ 36
Average Months to Expiration | month	5	6
Derivative Liability, Notional Amount	$ 3,650	$ 5,600
Average Fixed Pay Rate	3.35%	3.15%
Average Maturity (Years)	8 years 2 months 27 days	6 years 4 months 22 days
Less Than or Equal to One Year [Member] | Receiver Swaption [Member]
Cost		$ 18
Fair Value		$ 29
Average Months to Expiration | month		5
Derivative Liability, Notional Amount		$ 4,250
Average Fixed Pay Rate		1.78%
Average Receive Rate (LIBOR)		3M
Average Maturity (Years)		6 years 4 months 7 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 Swaption [Member]
Cost		$ 32
Fair Value		$ 10
Average Months to Expiration | month		16
Derivative Liability, Notional Amount		$ 1,200
Average Fixed Pay Rate		3.87%
Average Maturity (Years)		5 years 30 days
Greater Than One Year and Less Than or Equal to Three Years [Member] | Payer Swaption [Member]
Average Receive Rate (LIBOR)		3M

Derivative and Other Hedging 40

Derivative and Other Hedging Instruments (US Treasury Securities) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
U.S. Treasury securities, net	$ (522)	$ (2,936)
5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	597
7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(90)
10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(1,033)
Fair Value Hedging [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(522)	(2,936)
Fair Value Hedging [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	605	(4,645)
Fair Value Hedging [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(88)	(718)
Fair Value Hedging [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(1,039)	2,427
At Par Value [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(526)	(2,981)
At Par Value [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net		(4,674)
At Par Value [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net		(717)
At Par Value [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net		2,410
At Cost Basis [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(513)	(2,945)
At Cost Basis [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	604	(4,650)
At Cost Basis [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(89)	(717)
At Cost Basis [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	$ (1,028)	$ 2,422

Derivative and Other Hedging 41

Derivative and Other Hedging Instruments (TBA Securities by Coupon and Issuer) (Details) - TBA and Forward Settling Agency Securities [Member] - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Derivative, Notional Amount	$ 7,128	$ 14,412
Cost Basis	7,265	14,576
Net long TBA position, at fair value	7,385	14,768
TBA, net carrying value	120	192
15 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	(262)	3,260
Cost Basis	(262)	3,348
Net long TBA position, at fair value	(264)	3,360
TBA, net carrying value	(2)	12
30 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	7,390	11,152
Cost Basis	7,527	11,228
Net long TBA position, at fair value	7,649	11,408
TBA, net carrying value	122	180
Fannie Mae [Member]
Derivative [Line Items]
Derivative, Notional Amount	6,572	15,127
Cost Basis	6,698	15,316
Net long TBA position, at fair value	6,807	15,509
TBA, net carrying value	109	193
Freddie Mac [Member]
Derivative [Line Items]
Derivative, Notional Amount	256	(715)
Cost Basis	255	(740)
Net long TBA position, at fair value	264	(741)
TBA, net carrying value	9	(1)
Ginnie Mae [Member]
Derivative [Line Items]
Derivative, Notional Amount	300
Cost Basis	312
Net long TBA position, at fair value	314
TBA, net carrying value	2
2.5% Coupon [Member] | 15 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	(409)	962
Cost Basis	(414)	968
Net long TBA position, at fair value	(417)	980
TBA, net carrying value	(3)	12
3.0% Coupon [Member] | 15 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	143	2,779
Cost Basis	148	2,889
Net long TBA position, at fair value	149	2,888
TBA, net carrying value	1	(1)
3.0% Coupon [Member] | 30 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	3,441	5,254
Cost Basis	3,424	5,259
Net long TBA position, at fair value	3,480	5,313
TBA, net carrying value	56	54
3.5% Coupon [Member] | 15 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	4	(468)
Cost Basis	4	(495)
Net long TBA position, at fair value	4	(494)
TBA, net carrying value	0	1
3.5% Coupon [Member] | 30 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,873	7,902
Cost Basis	1,900	8,151
Net long TBA position, at fair value	1,954	8,232
TBA, net carrying value	54	81
4.0% Coupon [Member] | 15 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount		(13)
Cost Basis		(14)
Net long TBA position, at fair value		(14)
TBA, net carrying value		0
4.0% Coupon [Member] | 30 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount	2,076	(1,853)
Cost Basis	2,203	(2,019)
Net long TBA position, at fair value	2,215	(1,974)
TBA, net carrying value	$ 12	45
4.5% Coupon [Member] | 30 Year Maturity [Member]
Derivative [Line Items]
Derivative, Notional Amount		(151)
Cost Basis		(163)
Net long TBA position, at fair value		(163)
TBA, net carrying value		$ 0

Derivative and Other Hedging 42

Derivative and Other Hedging Instruments (Effect Of Derivative Instruments Not Designated As Hedges On Comprehensive Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	$ (795)	$ (59)	$ (1,116)	$ (761)
Gain (loss) on REIT Equity Securities		2		71
Gain Loss on Other Debt	7	6	16	(6)
Interest Only And Principal Only Strip [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Unrealized Gain (Loss) on Securities	10	4	14	31
Put Option [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount		(100)
Additions		0		(150)
Settlement, Expirations or Exercise		100		150
Notional Amount		0		0
Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount			6,800
Additions	0	(1,500)	(500)	(3,750)
Settlement, Expirations or Exercise	1,800	3,000	3,650	11,850
Amount Gain/(Loss) Recognized in Income on Derivatives	(23)	(14)	(27)	(160)
TBA and Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	6,941	17,811	14,412	2,119
Additions	33,403	44,438	97,270	134,760
Settlement, Expirations or Exercise				(119,620)
Notional Amount	7,128	17,259	7,128	17,259
Amount Gain/(Loss) Recognized in Income on Derivatives	213	33	337	637
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Settlement, Expirations or Exercise	(33,216)	(44,990)	(104,554)
Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount			43,700
Additions	(1,450)	(3,625)	(4,950)	(12,325)
Settlement, Expirations or Exercise	1,200	11,300	3,475	15,350
Notional Amount	45,175		45,175
Amount Gain/(Loss) Recognized in Income on Derivatives	(966)	(26)	(1,278)	(993)
Receiver Swaption [Member] | Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Additions		750	0	2,500
Settlement, Expirations or Exercise		0	(4,250)
Amount Gain/(Loss) Recognized in Income on Derivatives		0	4
Future [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(730)	(730)	(730)	(1,730)
Additions	(730)	(730)	(2,190)	(2,190)
Settlement, Expirations or Exercise	730	730	2,190	3,190
Notional Amount	(730)	(730)	(730)	(730)
Amount Gain/(Loss) Recognized in Income on Derivatives	(23)	0	(28)	(55)
Put Option [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount		0		0
Other derivative instruments [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives			(4)	7
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(5,450)	(7,650)	(6,800)	(14,250)
Notional Amount	(3,650)	(6,150)	(3,650)	(6,150)
Not Designated as Hedging Instrument [Member] | Receiver Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount		1,750	4,250
Notional Amount	0	2,500	0	2,500
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(44,925)	(47,900)	(43,700)	(43,250)
Notional Amount	(45,175)	(40,225)	(45,175)	(40,225)
Short [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(2,250)	(5,988)	(5,392)	(2,007)
Additions	(4,335)	(5,974)	(10,732)	(21,830)
Settlement, Expirations or Exercise	5,284	7,263	14,823	19,138
Notional Amount	(1,301)	(4,699)	(1,301)	(4,699)
Amount Gain/(Loss) Recognized in Income on Derivatives	(25)	(44)	(89)	(262)
Long [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Trading Securities	775	1,223	775	1,223
Long [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	29	(8)	(35)	72
Trading Securities		1,223		1,223	$ 5,192	$ 2,411	$ 1,250	$ 3,927
Trading Securities Added During the Period	4,704	5,028	31,915	9,963
Notional Amount Of Trading Securities Settlement Expiration During The Period	$ (9,121)	$ (5,055)	$ (33,551)	$ (12,667)

Pledged Assets (Narrative) (Det

Pledged Assets (Narrative) (Details) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Pledged Assets [Abstract]
Risk Of Repurchase Agreement To Stockholders Equity	6.00%	5.00%
Risk of interest swap and swaption agreements to stockholders' equity	$ 0.01

Pledged Assets Repurchase Agree

Pledged Assets Repurchase Agreements with Counterparties Greater than or Equal to 5% of Equity at Risk (Details) $ in Millions	Sep. 30, 2015USD ($)days	Dec. 31, 2014USD ($)days
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Securities Sold under Agreements to Repurchase	$ 41,014	$ 50,296
Risk Of Repurchase Agreement To Stockholders Equity	6.00%	5.00%
Weighted Average Days to Maturity | days	199	138
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	$ 4,585
Counterparty Exposure	$ 496
Risk Of Repurchase Agreement To Stockholders Equity	6.00%
Weighted Average Days to Maturity | days	1,076

Pledged Assets (Assets Pledged

Pledged Assets (Assets Pledged as Collateral) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	$ 47,319	$ 51,629
Accrued interest on pledged securities	137	153
Restricted cash	1,413	713
Total Fair Value Of Agency Securities Pledged And Accrued Interest	51,128	56,394
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	46,798	51,037
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	247	69
Accrued interest on pledged securities		2
Restricted cash	1,356	698
Total Fair Value Of Agency Securities Pledged And Accrued Interest	2,057	1,319
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Accrued interest on pledged securities	130	147
Total Fair Value Of Agency Securities Pledged And Accrued Interest	47,416	53,094
Variable Interest Entity, Primary Beneficiary [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	1,088	1,266
Accrued interest on pledged securities	3	4
Total Fair Value Of Agency Securities Pledged And Accrued Interest	1,091	1,270
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	531	702
Accrued interest on pledged securities	2
Total Fair Value Of Agency Securities Pledged And Accrued Interest	564	711
Includes Sold But Not Yet Settled Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	48,664	53,074
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	914	2,454
US Treasury Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	462	1,904
US Treasury Securities [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	452	550
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Accrued interest on pledged securities	2
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash	26	6
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash	31	9
Excluding Cash Received [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash	$ 1,413	$ 713

Pledged Assets (Securities Pled

Pledged Assets (Securities Pledged as Collateral) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Offsetting Assets and Liabilities [Line Items]
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repo	$ 256	$ 179
Security Owned and Pledged as Collateral, Fair Value	47,260	52,941
Agency Securities Pledged As Collateral Amortized Cost	46,739	52,397
Agency Securities Pledged As Collateral Accrued Interest	130	147
Maturity Less than 30 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	18,800	14,659
Agency Securities Pledged As Collateral Amortized Cost	18,548	14,509
Agency Securities Pledged As Collateral Accrued Interest	51	41
Maturity 31 To 59 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	5,626	10,906
Agency Securities Pledged As Collateral Amortized Cost	5,582	10,784
Agency Securities Pledged As Collateral Accrued Interest	16	30
Maturity 60 To 90 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	4,820	10,205
Agency Securities Pledged As Collateral Amortized Cost	4,774	10,109
Agency Securities Pledged As Collateral Accrued Interest	13	28
Maturity over 90 days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	17,552	15,267
Agency Securities Pledged As Collateral Amortized Cost	17,375	15,096
Agency Securities Pledged As Collateral Accrued Interest	49	43
Maturity Overnight [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	209	1,904
Agency Securities Pledged As Collateral Amortized Cost	207	1,899
Agency Securities Pledged As Collateral Accrued Interest	0	5
2 Days to 1 Month [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	253	0
Agency Securities Pledged As Collateral Amortized Cost	253	0
Agency Securities Pledged As Collateral Accrued Interest	1	0
Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	46,798	51,037
Agency Securities Pledged As Collateral Amortized Cost	46,279	50,498
Agency Securities Pledged As Collateral Accrued Interest	129	142
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	462	1,904
Agency Securities Pledged As Collateral Amortized Cost	460	1,899
Agency Securities Pledged As Collateral Accrued Interest	$ 1	$ 5

Pledged Assets (Assets Pledge47

Pledged Assets (Assets Pledged from Counterparties) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Offsetting Assets and Liabilities [Line Items]
Federal Home Loan Bank Stock	$ 140
Available-for-sale Securities Pledged as Collateral	47,319	$ 51,629
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	1,309	5,363
Restricted Cash and Cash Equivalents	1,413	713
Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	1,309
Restricted Cash and Securities Pledged	1,309	5,481
Restricted Cash and Cash Equivalents	0	28
Derivative [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	43
Restricted Cash and Securities Pledged	0	118
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	914	2,454
US Treasury Securities [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	1,309	5,410
Reverse Repurchase Agreements [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	1,309	5,363
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	247	69
Restricted Cash and Cash Equivalents	1,356	698
Derivative [Member] | US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	452	550
Derivative [Member] | US Treasury Securities [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Available-for-sale Securities Pledged as Collateral	0	47
Derivative [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	$ 0	$ 28

Pledged Assets (Offsetting Asse

Pledged Assets (Offsetting Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Offsetting Assets and Liabilities [Line Items]
Collateral Received	$ (4)
Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	1,484	$ 5,429
Net Amounts of Assets Presented in the Consolidated Balance Sheets	1,484	5,429
Financial Instruments	(1,480)	(4,784)
Collateral Received		(611)
Net Amount	0	34
Assets [Member] | Interest Rate Swap [Member] | Swaption [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	21	211
Net Amounts of Assets Presented in the Consolidated Balance Sheets	21	211
Financial Instruments	(21)	(94)
Collateral Received	0	(83)
Net Amount	0	34
Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	46,039	51,176
Net Amounts of Assets Presented in the Consolidated Balance Sheets	46,039	51,176
Financial Instruments	(1,480)	(4,784)
Collateral Received	(44,559)	(46,388)
Net Amount	0
Liability [Member] | Interest Rate Swap [Member] | Swaption [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	1,523	880
Net Amounts of Assets Presented in the Consolidated Balance Sheets	1,523	880
Financial Instruments	(21)	(94)
Collateral Received	(1,502)	(782)
Net Amount		4
Liability [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Net Amount	0
Reverse Repurchase Agreements [Member] | Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	1,463	5,218
Net Amounts of Assets Presented in the Consolidated Balance Sheets	1,463	5,218
Financial Instruments	(1,459)	(4,690)
Collateral Received	(4)	(528)
Repurchase Agreements [Member] | Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	44,516	50,296
Net Amounts of Assets Presented in the Consolidated Balance Sheets	44,516	50,296
Financial Instruments	(1,459)	(4,690)
Collateral Received	$ (43,057)	$ (45,606)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between hierarchy levels	0
Agency securities	$ 53,729	$ 55,482
Agency securities transferred to consolidated VIEs	1,088	1,266
U.S. Treasury securities	787	2,427
TBA securities	143	408
Derivative Liability	1,536	890
Debt of consolidated variable interest entities, at fair value	626	761
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	1,309	5,363
Interest rate swaps	143	408
REIT equity securities, at fair value	34	68
U.S. Treasury futures	1,536	890
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligation to return securities borrowed under reverse repurchase agreements, at fair value		5,363
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	821	2,495
Total liabilities	1,318	5,368
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	54,960	57,156
Total liabilities	2,153	1,646
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
TBA securities	2
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]
TBA securities	2	5
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	21	75
Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury futures	1,523	880
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0	136
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	1,523	880
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury futures	2	5
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	$ 122	197
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]
Derivative Liability		$ 5

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended		12 Months Ended
	May. 31, 2014	Jun. 30, 2012	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	May. 05, 2014	Apr. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Authorized			10,000,000		10,000,000
Preferred Stock Authorized, but not Issued			3,100,000
Issuance of preferred stock			$ 0	$ 169
Preferred Stock, Shares Issued			6,900,000		6,900,000
Preferred Stock, Value, Issued			$ 336		$ 336
Preferred Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance			6,900,000
Sale of Stock, Price Per Share							$ 24.2125
Series A Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Dividend Rate, Percentage					8.00%
Issuance of preferred stock		$ 167
Preferred Stock, Liquidation Preference Per Share			$ 25
Preferred Class B [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance			8,050
Preferred Stock, Dividend Rate, Percentage			7.75%
Preferred Stock, Shares Issued						7,000,000
Share Price						$ 24.2125
Preferred Stock, Value, Issued						$ 169
Series B Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Liquidation Preference Per Share						$ 25
Preferred stock, percent interest per share	0.10%

Stockholders' Equity (Common St

Stockholders' Equity (Common Stock Repurchase Program) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average repurchase price (in dollars per share)	$ 19.08	$ 19.57	$ 22.10
Repurchase of common stock, value		$ 124	$ 74
Payments for Repurchase of Common Stock	$ 45	124	$ 74
Remaining amount authorized for repurchase	$ 868	$ 868
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of common stock shares	2.4	6.3	3.4
Repurchase of common stock, value		$ 1

Stockholders' Equity (Accumulat

Stockholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Accumulated OCI Balance	$ 495	$ (203)	$ 495	$ (203)	$ 4	$ 430	$ 12	$ (1,383)
OCI before reclassifications	467	(253)	(14)	1,059
Amounts reclassified from accumulated OCI	24	38	79	121
Total Accumulated OCI Balance	63	24	104	104
Agency Securities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning OCI Balance	89	225	570	(1,087)
OCI before reclassifications	428	(239)	(39)	1,076
Amounts reclassified from accumulated OCI	39	(14)	25	(17)
Ending OCI Balance	556	(28)	556	(28)
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	61	(175)	61	(175)	$ 85	$ 140	$ 213	$ 296
Interest Rate Swap [Member] | Agency Securities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
OCI before reclassifications	$ 428	$ (239)	$ (39)	$ 1,076

Subsequent Event (Details)

Subsequent Event (Details) - $ / shares	Oct. 13, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Subsequent Event [Line Items]
Dividends declared per common share		$ 0.6	$ 0.65	$ 1.88000000	$ 1.95000000
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends declared per common share	$ 0.20