Document and Entity Information - USD ($) $ in Billions	12 Months Ended
Document and Entity Information - USD ($) $ in Billions	Dec. 31, 2015	Jan. 31, 2016	Jun. 30, 2015
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q4
Entity Registrant Name	American Capital Agency Corp
Entity Central Index Key	0001423689
Entity Filer Category	Large Accelerated Filer
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		346,450,083
Trading Symbol	AGNC
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 5.9

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Assets:
Agency securities, at fair value (including pledged securities of $48,380 and $51,629, respectively)	$ 51,331	$ 55,482
Agency securities transferred to consolidated variable interest entities, at fair value (pledged securities)	1,029	1,266
Non-agency securities, at fair value (including pledged securities of $113 and $0, respectively)	113	0
U.S. Treasury securities, at fair value (including pledged securities of $25 and $2,375, respectively)	25	2,427
REIT equity securities, at fair value	33	68
Cash and cash equivalents	1,110	1,720
Restricted cash and cash equivalents	1,281	713
Derivative assets, at fair value	81	408
Receivable for securities sold (including pledged securities of $0 and $79, respectively)	0	239
Receivable under reverse repurchase agreements	1,713	5,218
Other assets	305	225
Total assets	57,021	67,766
Liabilities:
Repurchase Agreements	41,754	50,296
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	3,753	0
Debt of consolidated variable interest entities, at fair value	595	761
Payable for agency securities purchased	182	843
Derivative liabilities, at fair value	935	890
Dividend payable	74	85
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	1,696	5,363
Accounts payable and other accrued liabilities	61	100
Total liabilities	49,050	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; 337.5 and 352.8 shares issued and outstanding, respectively	3	4
Additional paid-in capital	10,048	10,332
Retained deficit	(2,350)	(1,674)
Accumulated other comprehensive income	(66)	430
Total stockholders' equity	7,971	9,428
Total liabilities and stockholders' equity	$ 57,021	$ 67,766

Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Available-for-sale Securities Pledged as Collateral	$ 48,380	$ 51,629
Non-Agency Securities Pledged as Collateral	113	0
Trading Securities Pledged as Collateral	25	2,375
Assets Pledged included in Receivable for Securities Sold	$ 0	$ 79
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	10.0	10.0
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	600.0	600.0
Common Stock, Shares, Issued	337.5	352.8
Common Stock, Shares, Outstanding	337.5	352.8

Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest income:
Interest income	$ 374	$ 295	$ 414	$ 383	$ 331	$ 357	$ 385	$ 399	$ 1,466	$ 1,472	$ 2,193
Interest expense	86	77	81	86	81	88	95	108	330	372	536
Net interest income	288	218	333	297	250	269	290	291	1,136	1,100	1,657
Other income, net:
Gain (loss) on sale of agency securities, net	2	(39)	(22)	36	34	14	22	(19)	(23)	51	(1,408)
Gain (loss) on derivative instruments and other securities, net	331	(778)	237	(549)	(572)	(51)	(244)	(378)	(759)	(1,243)	1,191
Total other income, net	333	(817)	215	(513)	(538)	(37)	(222)	(397)	(782)	(1,192)	(217)
Expenses:
Management fees	28	29	29	30	30	30	30	29	116	119	136
General and administrative expenses	5	5	7	6	5	5	6	6	23	22	32
Total expenses	33	34	36	36	35	35	36	35	139	141	168
Net income (loss)	588	(633)	512	(252)	(323)	197	32	(141)	215	(233)	1,259
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest									215	(233)	1,272
Excise and REIT Income tax									0	0	13
Dividend on preferred stock	7	7	7	7	7	7	5	3	28	23	14
Net income (loss) available (attributable) to common stockholders	581	(640)	505	(259)	(330)	190	27	(144)	187	(256)	1,245
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	583	(467)	872	(391)	(599)	253	(790)	(521)	597	(1,657)	3,127
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, De-Designated Interest Rate Swaps									(101)	(156)	(189)
Unrealized gain on derivative instruments, net	22	24	26	29	35	38	40	43	101	156	189
Other comprehensive income (loss)	(561)	491	(846)	420	634	(215)	830	564	(496)	1,813	(2,938)
Comprehensive income (loss)	27	(142)	(334)	168	311	(18)	862	423	(281)	1,580	(1,679)
Comprehensive income (loss) available (attributable) to common stockholders	$ 20	$ (149)	$ (341)	$ 161	$ 304	$ (25)	$ 857	$ 420	$ (309)	$ 1,557	$ (1,693)
Weighted average number of common shares outstanding-basic and diluted (shares)	341.6	347.8	352.1	352.8	352.8	352.8	352.8	354.8	348.6	353.3	379.1
Net loss per common share - basic and diluted (dollars per share)	$ 1.70	$ (1.84)	$ 1.43	$ (0.73)	$ (0.94)	$ 0.54	$ 0.08	$ (0.41)	$ 0.54	$ (0.72)	$ 3.28
Dividends declared per common share	$ 0.60	$ 0.60	$ 0.62	$ 0.66	$ 0.66	$ 0.65	$ 0.65	$ 0.65

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, 2012	$ 10,896	$ 167	$ 3	$ 9,460	$ (289)	$ 1,555
Balance, Preferred Stock, shares at Dec. 31, 2012		6.9
Balance, Common Stock, shares at Dec. 31, 2012			338.9
Net income (loss)	1,259				1,259
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(3,127)					(3,127)
Amounts reclassified from accumulated OCI	189					189
Stock Issued During Period, Shares, New Issues			57.5
Stock Issued During Period, Value, New Issues	1,803		$ 1	1,802
Issuance of preferred stock	0
Repurchase of common stock	(856)			856
Payments for Repurchase of Common Stock	856
Repurchase of common stock shares			40.2
Preferred dividends declared	(14)				14
Common dividends declared	(1,453)				1,453
Balance, value at Dec. 31, 2013	8,697	$ 167	$ 4	10,406	(497)	(1,383)
Balance, Preferred Stock, shares at Dec. 31, 2013		6.9
Balance, Common Stock, shares at Dec. 31, 2013			356.2
Net income (loss)	(233)				(233)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	1,657					1,657
Amounts reclassified from accumulated OCI	156					156
Issuance of preferred stock	169	$ 169
Repurchase of common stock	(74)			74
Payments for Repurchase of Common Stock	74
Repurchase of common stock shares			3.4
Preferred dividends declared	(23)				23
Common dividends declared	(921)				921
Balance, value at Dec. 31, 2014	$ 9,428	$ 336	$ 4	10,332	(1,674)	430
Balance, Preferred Stock, shares at Dec. 31, 2014	6.9	6.9
Balance, Common Stock, shares at Dec. 31, 2014	352.8		352.8
Net income (loss)	$ 215				215
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(597)					(597)
Amounts reclassified from accumulated OCI	101					101
Issuance of preferred stock	0
Repurchase of common stock	(285)		$ (1)	(284)
Payments for Repurchase of Common Stock	285
Repurchase of common stock shares			(15.3)
Preferred dividends declared	(28)				(28)
Common dividends declared	(863)				(863)
Balance, value at Dec. 31, 2015	$ 7,971	$ 336	$ 3	$ 10,048	$ (2,350)	$ (66)
Balance, Preferred Stock, shares at Dec. 31, 2015	6.9	6.9
Balance, Common Stock, shares at Dec. 31, 2015	337.5		337.5

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Cash Flows [Abstract]
Interest paid	$ 215	$ 217	$ 347
Taxes paid	1	3	25
Operating activities:
Net income (loss)	215	(233)	1,259
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of agency securities premiums and discounts, net	408	472	517
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, De-Designated Interest Rate Swaps	101	156	189
(Gain) loss on sale of agency securities, net	23	(51)	1,408
Loss on derivative instruments and other securities, net	759	1,243	(1,191)
(Increase) decrease in other assets	(83)	55	(24)
Increase (decrease) in accounts payable and other accrued liabilities	1	(18)	325
Accretion of discounts on debt of consolidated variable interest entities	4	(2)	18
Net cash provided by operating activities	1,428	1,622	2,501
Investing activities:
Purchases of agency securities	(32,770)	(26,349)	(76,892)
Payments To Acquire Non- Agency Mortgage Backed Securities	(116)	0	0
Proceeds from sale of agency securities	27,794	30,587	79,456
Principal collections on agency securities	7,922	7,358	10,589
Purchases of U.S. Treasury securities	(49,724)	(51,511)	(68,261)
Proceeds from sale of U.S. Treasury securities	48,354	56,068	54,952
Net proceeds from (payments on) reverse repurchase agreements	3,505	(3,337)	9,937
Net proceeds from (payments on) other derivative instruments	(300)	313	(1,007)
Purchases of REIT equity securities	(11)	(234)	(197)
Proceeds from sale of REIT equity securities	35	416	0
(Increase) decrease in restricted cash and cash equivalents	(568)	(612)	298
Other investing cash flows, net	(28)	(350)	0
Net cash provided by investing activities	4,093	12,349	8,875
Financing activities:
Proceeds from repurchase arrangements, net	380,580	291,736	564,971
Repayments on repurchase agreements	(389,122)	(304,973)	(575,916)
Proceeds from Federal Home Loan Bank Advances	12,957	0	0
Repayments of Federal Home Loan Bank Borrowings	(9,204)	0	0
Proceeds from debt of consolidated variable interest entities	0	0	203
Repayments on debt of consolidated variable interest entities	(155)	(158)	(209)
Net proceeds from preferred stock issuance	0	169	0
Net proceeds from common stock issuance	0	0	1,803
Payments for common stock repurchases	(285)	(74)	(856)
Cash dividends paid	(902)	(1,094)	(1,659)
Net cash used in financing activities	(6,131)	(14,394)	(11,663)
Net change in cash and cash equivalents	(610)	(423)	(287)
Cash and cash equivalents at beginning of period	1,720	2,143	2,430
Cash and cash equivalents at end of period	$ 1,110	$ 1,720	$ 2,143

Unaudited Interim Consolidated Financial Statements

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Unaudited Interim Consolidated Financial Statements

Quarterly Results (Unaudited)

The following is a presentation of the quarterly results of operations and comprehensive income for fiscal years 2015 and 2014 (in millions, except per share data).



	Quarter Ended
	March 31, 2015			June 30, 2015			September 30, 2015			December 31, 2015
Interest income:
Interest income	$	383		$	414		$	295		$	374
Interest expense	86			81			77			86
Net interest income	297			333			218			288
Other gain (loss):
Gain (loss) on sale of agency securities, net	36			(22		)	(39		)	2
Gain (loss) on derivative instruments and other securities, net	(549		)	237			(778		)	331
Total other gain (loss), net	(513		)	215			(817		)	333
Expenses:
Management fees	30			29			29			28
General and administrative expenses	6			7			5			5
Total expenses	36			36			34			33
Net income (loss)	(252		)	512			(633		)	588
Dividend on preferred stock	7			7			7			7
Net income (loss) available (attributable) to common shareholders	$	(259	)	$	505		$	(640	)	$	581

Net income (loss)	$	(252	)	$	512		$	(633	)	$	588
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities, net	391			(872		)	467			(583		)
Unrealized gain on derivative instruments, net	29			26			24			22
Other comprehensive income (loss)	420			(846		)	491			(561		)
Comprehensive income (loss)	168			(334		)	(142		)	27
Dividend on preferred stock	7			7			7			7
Comprehensive income (loss) available (attributable) to common shareholders	$	161		$	(341	)	$	(149	)	$	20
Weighted average number of common shares outstanding-basic and diluted	352.8			352.1			347.8			341.6
Net income (loss) per common share - basic and diluted	$	(0.73	)	$	1.43		$	(1.84	)	$	1.70
Comprehensive income (loss) per common share - basic and diluted	$	0.46		$	(0.97	)	$	(0.43	)	$	0.06
Dividends declared per common share	$	0.66		$	0.62		$	0.60		$	0.60



	Quarter Ended
	March 31, 2014			June 30, 2014			September 30, 2014			December 31, 2014
Interest income:
Interest income	$	399		$	385		$	357		$	331
Interest expense	108			95			88			81
Net interest income	291			290			269			250
Other loss:
Gain (loss) on sale of agency securities, net	(19		)	22			14			34
Loss on derivative instruments and other securities, net	(378		)	(244		)	(51		)	(572		)
Total other loss, net	(397		)	(222		)	(37		)	(538		)
Expenses:
Management fees	29			30			30			30
General and administrative expenses	6			6			5			5
Total expenses	35			36			35			35
Net income (loss)	(141		)	32			197			(323		)
Dividend on preferred stock	3			5			7			7
Net income (loss) available (attributable) to common shareholders	$	(144	)	$	27		$	190		$	(330	)

Net income (loss)	$	(141	)	$	32		$	197		$	(323	)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities, net	521			790			(253		)	599
Unrealized gain on derivative instruments, net	43			40			38			35
Other comprehensive income (loss)	564			830			(215		)	634
Comprehensive income (loss)	423			862			(18		)	311
Dividend on preferred stock	3			5			7			7
Comprehensive income (loss) available (attributable) to common shareholders	$	420		$	857		$	(25	)	$	304
Weighted average number of common shares outstanding-basic and diluted	354.8			352.8			352.8			352.8
Net income (loss) per common share - basic and diluted	$	(0.41	)	$	0.08		$	0.54		$	(0.94	)
Comprehensive income (loss) per common share - basic and diluted	$	1.18		$	2.43		$	(0.07	)	$	0.86
Dividends declared per common share	$	0.65		$	0.65		$	0.65		$	0.66

Organization	12 Months Ended
Organization	Dec. 31, 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 MBS"). 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 Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Consolidation Our consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States ("GAAP"). Our consolidated financial statements include the accounts of all subsidiaries and variable interest entities for which we are the primary beneficiary. Significant intercompany accounts and transactions have been eliminated. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and revenues and expenses during the period reported. Actual results could differ from those estimates. Earnings per Share Basic earnings per share ("EPS") is computed by dividing net income (loss) available (attributable) to common stockholders by the weighted average number of common shares outstanding during the period. Diluted EPS assumes the conversion, exercise or issuance of all potential common stock equivalents unless the effect is to reduce a loss or increase the income per share. Accumulated Other Comprehensive Income (Loss) Accounting Standards Codification ("ASC") Topic 220, Comprehensive Income ("ASC 220"), divides comprehensive income into net income and other comprehensive income (loss) ("OCI"), which includes unrealized gains and losses on securities classified as available-for-sale and unrealized gains and losses on derivative financial instruments that are designated and qualify for cash flow hedge accounting under ASC Topic 815, Derivatives and Hedging ("ASC 815"). During fiscal year 2011, we discontinued designating our derivative financial instruments, principally interest rate swaps, as cash flow hedges. For further information regarding our discontinuation of cash flow hedge accounting, see Derivatives Instruments below and Note 5. Cash and Cash Equivalents Cash and cash equivalents consist of unrestricted demand deposits and highly liquid investments with original maturities of three months or less. Cash and cash equivalents are carried at cost, which approximates fair value. Restricted Cash and Cash Equivalents Restricted cash and cash equivalents includes cash and cash equivalents pledged as collateral for clearing and executing trades, repurchase agreements and other borrowings, and interest rate swaps and other derivative instruments. Restricted cash and cash equivalents are carried at cost, which approximates fair value. Investment Securities 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 mortgage investment securities as part of our overall management of our investment portfolio. Accordingly, we typically designate our agency and non-agency securities (collectively referred to as "mortgage securities" or "investment 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 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. Non-agency securities in which we may invest consist of investment grade, AAA rated MBS backed by residential or commercial mortgages, for which the payment of principal and interest is not guaranteed by a GSE or government agency. Instead, a private institution such as a commercial bank will package residential or commercial mortgage loans and securitize them through the issuance of MBS. Investment grade, AAA rated non-agency MBS benefit from credit enhancements derived from structural elements, such as subordination, overcollateralization or insurance, but nonetheless carry a higher level of credit exposure than agency MBS. 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 flows of specific agency CMO securities. Principal-only securities represent our right to receive the contractual principal 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 mortgage securities based on a market approach using "Level 2" inputs from third-party pricing services and non-binding dealer quotes derived from common market pricing methods. Such methods incorporate, but are not limited to, reported trades and executable bid and asked prices for similar securities, benchmark interest rate curves, such as the spread to the U.S. Treasury rate and interest rate swap curves, convexity, duration and the underlying characteristics of the particular security, including coupon, periodic and life caps, rate reset period, issuer, additional credit support and expected life of the security. We estimate the fair value of our REIT equity securities on a market approach using "Level 1" inputs based on quoted market prices. Refer to Note 7 for further discussion of fair value measurements. We evaluate our mortgage 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. If either of the first two conditions exists as of the financial reporting date, the entire amount of the impairment loss, if any, is recognized in earnings as a realized loss and the cost basis of the security is adjusted to its fair value. However, with respect to the first condition, since the liquidity of the agency and AAA non-agency securities market allows us to obtain competitive bids and execute on a sale transaction typically within a day of making the decision to sell a security, we generally do not make decisions to sell specific mortgage securities until shortly prior to initiating a sell order. In some instances, we may sell specific agency securities by delivering the securities into existing short "to-be-announced" ("TBA") contracts. TBA market conventions require the identification of the specific securities to be delivered no later than 48 hours prior to settlement. If we settle a short TBA contract through the delivery of securities, we will generally identify the specific securities to be delivered within one to two days before the 48-hour deadline. If the third condition exists, the OTTI is separated into (i) the amount relating to credit loss (the "credit component") and (ii) the amount relating to all other factors (the "non-credit components"). Only the credit component is recognized in earnings, with the non-credit components recognized in OCI. However, in evaluating if the third condition exists, our investments in agency securities typically would not have a credit component since the principal and interest are guaranteed by a GSE and, therefore, any unrealized loss is not the result of a credit loss. In addition, since we designate our mortgage securities as available-for-sale securities with unrealized gains and losses recognized in OCI, any impairment loss for non-credit components is already recognized in OCI. We did not recognize any OTTI charges on our investment securities for fiscal years 2015, 2014 or 2013. 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 mortgage securities using a third-party service and market data. The third-party service estimates prepayment speeds using models that incorporate the forward yield curve, current mortgage rates and mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, interest rate volatility and other factors. We review the prepayment speeds estimated by the third-party service and compare the results to market consensus prepayment speeds, if available. We also consider historical prepayment speeds and current market conditions to validate the reasonableness of the prepayment speeds estimated by the third-party service and, based on our Manager's judgment, we may make adjustments to its estimates. Actual and anticipated prepayment experience is reviewed quarterly and effective yields are recalculated when differences arise between (i) our previously estimated future prepayments and (ii) the actual prepayments to date plus our currently estimated future prepayments. If the actual and estimated future prepayment experience differs from our prior estimate of prepayments, we are required to record an adjustment in the current period to the amortization or accretion of premiums and discounts for the cumulative difference in the effective yield through the reporting date. Repurchase Agreements We finance the acquisition of securities for our investment portfolio through repurchase transactions under master repurchase agreements. Pursuant to ASC Topic 860, Transfers and Servicing ("ASC 860"), we account for repurchase transactions as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest, as specified in the respective transactions. Our repurchase agreements typically have maturities of less than one year, but may extend up to five years or more. Interest rates under our repurchase agreements generally correspond to one, three or six month LIBOR plus or minus a fixed spread. The fair value of our repurchase agreements is assumed to equal cost as the interest rates are considered to be at market. Federal Home Loan Bank Advances Federal Home Loan Bank ("FHLB") advances are secured loans from the FHLB of Des Moines used to finance the acquisitions of investment securities. We account for FHLB advances as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest, as specified in the respective transactions. In April 2015, our wholly-owned captive insurance subsidiary, Old Georgetown Insurance Co., LLC ("OGI"), was approved as a member of the FHLB of Des Moines. The FHLBs provide a variety of products and services to their members, including short and long-term secured loans. In January 2016, the Federal Housing Finance Agency released its final rule on changes to regulations concerning FHLB membership criteria. The final rule terminates OGI's FHLB membership and requires repayment of all advances at the earlier of their contractual maturity dates or one year after the effective date of the final rule (February 2017). Interest rates under our FHLB advances generally correspond to the FHLB's Member Option Variable Rate or to one or three month LIBOR plus or minus a fixed spread. The fair value of our FHLB advances is assumed to equal cost as the interest rates are considered to be at market. Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We from time to time borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivatives Instruments below). We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on the balance sheet based on the value of the underlying borrowed securities as of the reporting date. Our reverse repurchase agreements generally mature daily. The fair value of our reverse repurchase agreements is assumed to equal cost as the interest rates are generally reset daily. Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate, prepayment and extension risks. The objective of our risk management strategy is to reduce fluctuations in net book value over a range of interest rate scenarios. In particular, we attempt to mitigate the risk of the cost of our variable rate liabilities increasing during a period of rising interest rates. The 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 on a generic pool basis in the TBA market and we utilize U.S. Treasury securities and U.S. Treasury futures contracts, primarily through short sales. We may also purchase or write put or call options on TBA securities and invest in mortgage and other types of derivatives, 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 fiscal year 2011, we entered into interest rate swap agreements typically with the intention of qualifying for hedge accounting under ASC 815. However, during fiscal year 2011 we elected to discontinue hedge accounting for our interest rate swaps. Upon discontinuation of hedge accounting, the net deferred loss related to our de-designated interest rate swaps remained in accumulated OCI and 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 agreement facilities. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate based on one, three or six-month LIBOR ("payer swaps") with terms up to 20 years. The floating rate we receive under our swap agreements has the effect of offsetting the repricing characteristics of our repurchase agreements and cash flows on such liabilities. Our swap agreements are privately negotiated in the over−the−counter ("OTC") market, 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" swaps using a combination of inputs from counterparty and third-party pricing models to estimate the net present value of the future cash flows using the forward interest rate yield curve in effect as of the end of the measurement period. We also incorporate both our own and our counterparties' nonperformance risk in estimating the fair value of our interest rate swaps. In considering the effect of nonperformance risk, we consider the impact of netting and credit enhancements, such as collateral postings and guarantees, and have concluded that our own and our counterparty risk is not significant to the overall valuation of these agreements. Interest rate swaptions We purchase interest rate swaptions generally to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. Interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay and receive interest rates in the future. Our swaption agreements typically provide us the option to enter into a pay fixed rate interest rate swap, which we refer as "payer swaptions." We may also enter into swaption agreements that provide us the option to enter into a receive fixed interest rate swap, which we refer to as "receiver swaptions." The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. The premium is valued at an amount equal to the fair value of the swaption that would have the effect of closing the position adjusted for nonperformance risk, if any. The difference between the premium and the fair value of the swaption is reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid. If we sell or exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the cash or the fair value of the underlying interest rate swap received and the premium paid. Our interest rate swaption agreements are privately negotiated in the OTC market and are not subject to central clearing. We estimate the fair value of interest rate swaptions using a combination of inputs from counterparty and third-party pricing models based on the fair value of the future interest rate swap that we have the option to enter into as well as the remaining length of time that we have to exercise the option, adjusted for non-performance risk, if any. TBA securities A TBA security is a forward contract for the purchase ("long position") or sale ("short position") of agency 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 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. Variable Interest Entities ASC Topic 810, Consolidation ("ASC 810"), requires an enterprise to consolidate a variable interest entity ("VIE") if it is deemed the primary beneficiary of the VIE. Further, ASC 810 requires a qualitative assessment to determine the primary beneficiary of a VIE and ongoing assessments of whether an enterprise is the primary beneficiary of a VIE as well as additional disclosures for entities that have variable interests in VIEs. We have entered into transactions involving CMO trusts, which are VIEs. We will consolidate a CMO trust if we are the CMO trust's primary beneficiary; that is, if we have a variable interest that provides us with a controlling financial interest in the CMO trust. An entity is deemed to have a controlling financial interest if the entity has the power to direct the activities of a VIE that most significantly impact the VIE's economic performance and the obligation to absorb losses of or right to receive benefits from the VIE that could potentially be significant to the VIE. As part of the qualitative assessment in determining if we have a controlling financial interest, we evaluate whether we control the selection of financial assets transferred to the CMO trust. For each of our consolidated CMO trusts we controlled the selection of the agency MBS transferred from our investment portfolio to an investment bank in exchange for cash proceeds and at the same time entered into a commitment with the investment bank to purchase to-be-issued securities collateralized by the agency MBS transferred, which resulted in our consolidation of the CMO trusts. Agency MBS transferred to consolidated VIEs are reported on our consolidated balance sheets in agency securities transferred to consolidated VIEs, at fair value and can only be used to settle the obligations of each respective VIE. We elected the option to account for the consolidated debt at fair value, with changes in fair value reflected in earnings during the period in which they occur, because we believe this election more appropriately reflects our financial position as both the consolidated assets and consolidated debt are presented in a consistent manner on our consolidated balance sheets. We estimate the fair value of the consolidated debt based on the fair value of the agency MBS transferred to consolidated VIEs, less the fair value of our retained interests, which are measured on a market approach using "Level 2" inputs from third-party pricing services and dealer quotes. The fair value of the agency MBS transferred to the consolidated VIEs and the fair value of our retained interests are based on more observable inputs than inputs used to independently determine the value of our consolidated debt. Manager Compensation Our management agreement provides for the payment to our Manager of a management fee and reimbursement of certain operating expenses, which are accrued and expensed during the period for which they are earned or incurred. Refer to Note 8 for the terms of our management agreement and the administrative services agreement between American Capital and our Manager. Income Taxes We elected to be taxed as a REIT under the provisions of the Internal Revenue Code and the corresponding provisions of state law, commencing with our initial tax year ended December 31, 2008. In order to continue to qualify as a REIT, we must annually distribute, in a timely manner to our stockholders, at least 90% of our taxable ordinary income, amongst other conditions. A REIT is not subject to tax on its earnings to the extent that it distributes its annual taxable income to its stockholders and as long as certain asset, income and stock ownership tests are met. We operate in a manner that will allow us to be taxed as a REIT. As permitted by the Internal Revenue Code, a REIT can designate dividends paid in the subsequent year as dividends of the current year if those dividends are both declared by the extended due date of the REIT's federal income tax return and paid to stockholders by the last day of the subsequent year. As a REIT, if we fail to distribute in any calendar year at least the sum of (i) 85% of our ordinary income for such year, (ii) 95% of our capital gain net income for such year and (iii) any undistributed taxable income from the prior year, we are subject to a non-deductible 4% excise tax on the excess of such required distribution over the sum of (a) the amounts actually distributed and, if applicable, (b) the amounts of income we retained and on which we have paid corporate income tax. Dividends declared by December 31 and paid by January 31 are treated as having been a distribution of our taxable income for the prior tax year. We and our wholly-owned subsidiary, American Capital Agency TRS, LLC ("AGNC TRS"), have made a joint election to treat AGNC TRS as a taxable REIT subsidiary. As such, AGNC TRS is subject to federal and state income tax. All other subsidiaries are disregarded entities for federal income tax purposes. As such, their assets, liabilities and income would generally be treated as our assets, liabilities and income for purposes of federal and state income taxes. We evaluate uncertain income tax positions, if any, in accordance with ASC Topic 740, Income Taxes ("ASC 740"). To the extent we incur interest and/or penalties in connection with our tax obligations, such amounts shall be classified as income tax expense on our consolidated statements of operations.

Investment Securities

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Investment Securities

As of December 31, 2015 and 2014, our investment portfolio consisted of $52.5 billion and $56.7 billion of 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 $14 million and $192 million as of December 31, 2015 and 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 5 for further details of our net TBA position as of December 31, 2015 and 2014.)

As of December 31, 2015 and 2014, the net unamortized premium balance on our MBS was $2.3 billion and $2.5 billion, respectively, including interest and principal-only securities.

The following tables summarize our investments in MBS as of December 31, 2015 and 2014 (dollars in millions):



	December 31, 2015
Investments in Mortgage-Backed Securities	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Agency MBS:
Fixed rate	$	50,576	$	339	$	(393	)	$	50,522
Adjustable rate	484		11		—			495
CMO	973		18		(1		)	990
Interest-only and principal-only strips	317		39		(3		)	353
Total agency MBS	52,350		407		(397		)	52,360
Non-agency MBS:
AAA non-agency	114		—		(1		)	113
Total MBS	$	52,464	$	407	$	(398	)	$	52,473



	December 31, 2014
Investments in Mortgage-Backed Securities	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Agency MBS:
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 MBS	$	56,148	$	791	$	(191	)	$	56,748



	December 31, 2015
Investments in Mortgage-Backed Securities	Fannie Mae			Freddie Mac			Ginnie Mae			Non-Agency			Total
Available-for-sale MBS:
MBS, par value	$	39,205		$	10,575		$	62		$	113		$	49,955
Unamortized discount	(32		)	(4		)	—			—			(36		)
Unamortized premium	1,707			519			1			1			2,228
Amortized cost	40,880			11,090			63			114			52,147
Gross unrealized gains	286			80			2			—			368
Gross unrealized losses	(283		)	(111		)	—			(1		)	(395		)
Total available-for-sale MBS, at fair value	40,883			11,059			65			113			52,120
MBS remeasured at fair value through earnings:
Interest-only and principal-only strips, amortized cost ¹	298			19			—			—			317
Gross unrealized gains	35			4			—			—			39
Gross unrealized losses	(2		)	(1		)	—			—			(3		)
Total MBS remeasured at fair value through earnings	331			22			—			—			353
Total MBS, at fair value	$	41,214		$	11,081		$	65		$	113		$	52,473
Weighted average coupon as of December 31, 2015 ²	3.62		%	3.69		%	3.18		%	3.50		%	3.63		%
Weighted average yield as of December 31, 2015 ³	2.79		%	2.77		%	1.97		%	3.33		%	2.78		%

________________________


1.	The underlying unamortized principal balance ("UPB" or "par value") of our interest-only securities was $1.0 billion and the weighted average contractual interest we are entitled to receive was 5.28% of this amount as of December 31, 2015. The par value of our principal-only securities was $207 million as of December 31, 2015.


2.	The weighted average coupon includes the interest cash flows from our interest-only securities and is stated as a percentage of par value (excluding the UPB of our interest-only securities) as of December 31, 2015.


3.	Incorporates a weighted average future constant prepayment rate assumption of 8% based on forward rates as of December 31, 2015.



	December 31, 2014
Investments in Mortgage-Backed Securities	Fannie Mae			Freddie Mac			Ginnie Mae			Total
Available-for-sale MBS:
MBS, par value	$	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 MBS, at fair value	45,075			11,159			112			56,346
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 MBS measured at fair value through earnings	376			26			—			402
Total 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 securities 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 securities was $242 million as of December 31, 2014.


2.	The weighted average coupon includes the interest cash flows from our interest-only securities and is stated as a percentage of par value (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 investment securities are generally shorter than their stated contractual maturities. Actual maturities are affected by the contractual lives of the underlying mortgages, periodic contractual principal payments and principal prepayments. As of December 31, 2015 and 2014, our weighted average expected constant prepayment rate ("CPR") over the remaining life of our aggregate investment portfolio was 8% and 9%, respectively. Our estimates differ materially for different types of securities and thus individual holdings have a wide range of projected CPRs.

The following table summarizes our investments classified as available-for-sale as of December 31, 2015 and 2014 according to their estimated weighted average life classification (dollars in millions):



	December 31, 2015						December 31, 2014
Estimated Weighted Average Life of Securities 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	$	167	$	163	4.02%	2.66%	$	289	$	280	4.08%	2.62%
> 3 years and ≤ 5 years	17,497		17,343		3.27%	2.40%	22,153		21,820		3.26%	2.40%
> 5 years and ≤10 years	34,206		34,391		3.67%	2.93%	33,271		33,055		3.73%	2.92%
> 10 years	250		250		3.56%	3.08%	633		621		3.28%	3.15%
Total	$	52,120	$	52,147	3.54%	2.75%	$	56,346	$	55,776	3.54%	2.72%

_______________________


1.	Excludes interest and principal-only strips.

The weighted average life of our interest-only securities was 6.1 and 6.0 years as of December 31, 2015 and 2014, respectively. The weighted average life of our principal-only securities was 8.0 and 8.1 years as of December 31, 2015 and 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 10 for a summary of changes in accumulated OCI for our available-for-sale securities for fiscal years 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 December 31, 2015 and 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
December 31, 2015	$	24,035	$	(200	)	$	6,793	$	(195	)	$	30,828	$	(395	)
December 31, 2014	$	778	$	(2	)	$	11,679	$	(186	)	$	12,457	$	(188	)

We did not recognize any OTTI charges on our investment securities for fiscal years 2015, 2014 and 2013. As of the end of each respective reporting period, a decision had not been made to sell any of our securities in an unrealized loss position and we did not believe it was more likely than not that we would be required to sell such securities before recovery of their amortized cost basis. The unrealized losses on our securities were not due to credit losses given the GSE guarantees and credit enhancements on our AAA non-agency securities, but rather were due to changes in interest rates and prepayment expectations. However, as we continue to actively manage our portfolio, we may recognize additional realized losses on our investment securities upon selecting specific securities to sell.

Gains and Losses

The following table is a summary of our net gain (loss) from the sale of securities classified as available-for-sale for fiscal years 2015, 2014 and 2013 (in millions):



	Fiscal Year
Securities Classified as Available-for-Sale	2015			2014			2013
MBS sold, at cost	$	(27,578	)	$	(30,123	)	$	(81,516	)
Proceeds from agency MBS sold ¹	27,555			30,174			80,108
Net gain (loss) on sale of MBS	$	(23	)