AGNC Investment (AGNC) 10-Q 3 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Entity Registrant Name	AGNC INVESTMENT CORP.
Entity Central Index Key	0001423689
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		536,412,404
Trading Symbol	AGNC
Entity Current Reporting Status	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Assets:
Agency securities, at fair value (including pledged securities of $89,471 and $78,619, respectively)	$ 93,044	$ 82,291
Agency securities transferred to consolidated variable interest entities, at fair value (pledged securities)	425	436
Credit risk transfer securities, at fair value (including pledged securities of $142 and $141, respectively)	1,129	1,012
Non-Agency securities, at fair value (including pledged securities of $45 and $45, respectively)	672	548
U.S. Treasury securities, at fair value (including pledged securities of $121 and $0, respectively)	121	46
Cash and cash equivalents	929	921
Restricted cash and cash equivalents	517	599
Derivative assets, at fair value	253	273
Receivable for investment securities sold (pledged securities)	439	489
Receivable under reverse repurchase agreements	20,430	21,813
Goodwill and other intangible assets, net	526	526
Other assets	322	287
Total assets	118,807	109,241
Liabilities:
Repurchase Agreements	86,685	75,717
Debt of consolidated variable interest entities, at fair value	266	275
Payable for investment securities purchased	1,125	1,204
Derivative liabilities, at fair value	53	84
Dividends payable	107	106
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	19,275	21,431
Accounts payable and other liabilities	795	518
Total liabilities	108,306	99,335
Stockholders' equity:
7.750% Series B Cumulative Redeemable Preferred Stock (aggregate liquidation preference of $175)	169	169
7.000% Series C Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock (aggregate liquidation preference of $325)	315	315
6.875% Series D Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock (aggregate liquidation preference of $235)	227	0
Common stock - $0.01 par value; 900 and 900 shares authorized, respectively; 536.3 shares issued and outstanding	5	5
Additional paid-in capital	13,795	13,793
Retained deficit	(3,467)	(3,433)
Accumulated other comprehensive loss	(543)	(943)
Total stockholders' equity	10,501	9,906
Total liabilities and stockholders' equity	$ 118,807	$ 109,241

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Millions, $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 89,966	$ 79,182
Preferred Stock B, Liquidation Preference, Value	175	175
Preferred Stock C, Liquidation Preference, Value	325	325
Preferred Stock D, Liquidation Preference, Value	$ 235	$ 0
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	900	900
Common Stock, Shares, Issued	536.3	536.3
Common Stock, Shares, Outstanding	536.3	536.3
Agency Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 89,471	$ 78,619
Credit Risk Transfer Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	142	141
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	45	45
US Treasury Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	617	437
Receivable for securities sold [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	439	489
Asset Pledged as Collateral [Member] | US Treasury Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 121	$ 0

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Dividends declared per common share	$ 0.54	$ 0.54
Interest income:
Interest income	$ 705	$ 431
Interest expense	541	206
Net interest income	164	225
Other gain (loss), net:
Gain (loss) on sale of investment securities, net	60	(2)
Unrealized gain (loss) on investment securities measured at fair value through net income, net	1,060	(523)
Gain (loss) on derivative instruments and other securities, net	(1,000)	738
Management Fee Income	0	4
Total other gain, net:	120	217
Expenses:
Compensation and benefits	10	10
Other operating expense	9	8
Total operating expense	19	18
Net income	265	424
Dividend on preferred stock	10	9
Net income available to common stockholders	255	415
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities, net	(400)	621
Comprehensive income (loss)	665	(197)
Comprehensive income (loss) available (attributable) to common stockholders	$ 655	$ (206)
Weighted average number of common shares outstanding - basic	536.7	391.3
Weighted average number of common shares outstanding - diluted	537.2	391.5
Net income per common share - basic	$ 0.48	$ 1.06
Net income per common share - diluted	$ 0.47	$ 1.06

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Series B Preferred Stock [Member]Preferred Stock [Member]	Series C Preferred Stock [Member]Preferred Stock [Member]	Series D Preferred Stock [Member]Preferred Stock [Member]
Balance, value at Dec. 31, 2017	$ 8,754	$ 4	$ 11,173	$ (2,562)	$ (345)	$ 169	$ 315	$ 0
Balance, Common Stock, shares at Dec. 31, 2017		391.3
Net income (loss)	424			424
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(621)				(621)
Adjustments to Additional Paid in Capital, Share-based Compensation and Exercise of Stock Options	1		1
Proceeds from Issuance of Preferred Stock and Preference Stock	0
Preferred dividends declared	(9)			(9)
Common dividends declared	(211)			(211)
Balance, value at Mar. 31, 2018	8,338	$ 4	11,174	(2,358)	(966)	169	315	0
Balance, Common Stock, shares at Mar. 31, 2018		391.3
Balance, value at Dec. 31, 2018	$ 9,906	$ 5	13,793	(3,433)	(943)	169	315	0
Balance, Common Stock, shares at Dec. 31, 2018	536.3	536.3
Net income (loss)	$ 265			265
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	400				400
Adjustments to Additional Paid in Capital, Share-based Compensation and Exercise of Stock Options	2		2
Proceeds from Issuance of Preferred Stock and Preference Stock	227
Preferred dividends declared	(10)			(10)
Common dividends declared	(289)			(289)
Balance, value at Mar. 31, 2019	$ 10,501	$ 5	$ 13,795	$ (3,467)	$ (543)	$ 169	$ 315	$ 227
Balance, Common Stock, shares at Mar. 31, 2019	536.3	536.3

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Cash Flows [Abstract]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 1,446	$ 1,358
Operating activities:
Net income (loss)	265	424
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of premiums and discounts on mortgage-backed securities, net	142	69
Amortization of intangible assets	0	1
Stock based compensation	2	1
(Gain) loss on sale of investment securities, net	(60)	2
Unrealized (gain) loss on investment securities measured at fair value through net income, net	(1,060)	523
(Gain) loss on derivative instruments and other securities, net	1,000	(738)
(Increase) decrease in other assets	(35)	3
Increase in accounts payable and other accrued liabilities	75	3
Net cash provided by operating activities	329	288
Investing activities:
Purchases of Agency mortgage-backed securities	(16,038)	(2,287)
Purchases of credit risk transfer and non-Agency securities	(499)	(215)
Proceeds from sale of Agency mortgage-backed securities	4,694	1,181
Proceeds from sale of credit risk transfer and non-Agency securities	297	208
Principal collections on Agency mortgage-backed securities	1,889	1,661
Principal collections on credit risk transfer and non-Agency securities	5	0
Payments on U.S. Treasury securities	(7,550)	(1,345)
Proceeds from U.S. Treasury securities	5,103	1,403
Net proceeds from reverse repurchase agreements	1,526	231
Net proceeds from (payments on) derivative instruments	(714)	466
Net proceeds from (payments on) other investing activity	0	(16)
Net cash (used in) provided by investing activities	(11,287)	1,287
Financing activities:
Proceeds from repurchase arrangements	930,289	243,168
Payments on repurchase agreements	(919,321)	(244,507)
Payments on debt of consolidated variable interest entities	(13)	(21)
Net proceeds from preferred stock issuance	227	0
Cash dividends paid	(298)	(220)
Net cash (used in) provided by financing activities	10,884	(1,580)
Net change in cash and cash equivalents	(74)	$ (5)
Cash and cash equivalents at end of period	$ 929

Unaudited Interim Consolidated

Unaudited Interim Consolidated Financial Statements	3 Months Ended
	Mar. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	Basis of Presentation The unaudited interim consolidated financial statements of AGNC Investment Corp. (referred throughout this report as the "Company," "we," "us" and "our") are prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Article 10 of Regulation S-X. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. In the opinion of management, all adjustments, consisting solely of normal recurring accruals, necessary for the fair presentation of financial statements for the interim period have been included. The current period’s results of operations are not necessarily indicative of results that ultimately may be achieved for the year.

Organization

Organization	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization We were organized in Delaware on January 7, 2008 and commenced operations on May 20, 2008 following the completion of our initial public offering. Our common stock is traded on The Nasdaq Global Select Market under the symbol "AGNC." We are internally-managed, and our principal objective is to provide our stockholders with attractive risk-adjusted returns through a combination of monthly dividends and tangible net book value accretion. We generate income from the interest earned on our investments, net of associated borrowing and hedging costs, and net realized gains and losses on our investment and hedging activities. We operate to qualify to be taxed as a real estate investment trust ("REIT") under the Internal Revenue Code of 1986, as amended (the "Internal Revenue Code"). As a REIT, we are required to distribute annually 90% of our taxable income. As a REIT, we will generally not be subject to U.S. federal or state corporate taxes on our taxable income to the extent that we distribute our annual taxable income to our stockholders on a timely basis. It is our intention to distribute 100% of our taxable income, after application of available tax attributes, within the limits prescribed by the Internal Revenue Code, which may extend into the subsequent tax year.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Investment Securities Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") guaranteed by the Federal National Mortgage Association ("Fannie Mae"), Federal Home Loan Mortgage Corporation ("Freddie Mac," and together with Fannie Mae, the "GSEs") or the Government National Mortgage Association ("Ginnie Mae"). CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third-party market participants, that transfer a portion of the risk associated with credit losses within pools of conventional residential mortgage loans from the GSEs and/or third parties to private investors. Unlike Agency RMBS, full repayment of the original principal balance of CRT securities is not guaranteed by a GSE or U.S. Government agency; rather, "credit risk transfer" is achieved by writing down the outstanding principal balance of the CRT securities if credit losses on a related pool of loans exceed certain thresholds. By reducing the amount that they are obligated to repay to holders of CRT securities, the GSEs and/or other third parties offset credit losses on the related loans. Non-Agency RMBS and CMBS (together, "Non-Agency MBS") are backed by residential and commercial mortgage loans, respectively, packaged and securitized by a private institution, such as a commercial bank. Non-Agency MBS typically benefit from credit enhancements derived from structural elements, such as subordination, overcollateralization or insurance, but nonetheless carry a higher level of credit exposure than Agency RMBS. All of our securities are reported at fair value on our consolidated balance sheet. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities , requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for securities pursuant to ASC Topic 825, Financial Instruments . Prior to fiscal year 2017, we primarily designated our investment securities as available-for-sale. On January 1, 2017, we began electing the fair value option of accounting for all investment securities acquired after fiscal year 2016. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income ("OCI"). Unrealized gains and losses on securities for which we elected the fair value option or are classified as trading are reported in net income through other gain (loss) during the period in which they occur. Upon the sale of a security designated as available-for-sale, we determine the cost of the security and the amount of unrealized gains or losses to reclassify out of accumulated OCI into earnings based on the specific identification method. In our view, the election of the fair value option simplifies the accounting for investment securities and more appropriately reflects the results of our operations for a reporting period, as the fair value changes for these assets are presented in a manner consistent with the presentation and timing of the fair value changes of our derivative instruments. We estimate the fair value of our investment securities based on prices provided by multiple third-party pricing services and non-binding dealer quotes (collectively "pricing sources"). These pricing sources use various valuation approaches, including market and income approaches, using "Level 2" inputs. The pricing sources primarily utilize a matrix pricing technique that interpolates the estimated fair value of our Agency RMBS based on observed quoted prices for forward contracts in the Agency RMBS "to-be-announced" market ("TBA securities") of the same coupon, maturity and issuer, adjusted to reflect the specific characteristics of the pool of mortgages underlying the Agency security, which may include maximum loan balance, loan vintage, loan-to-value ratio, geography and other characteristics as may be appropriate. The pricing sources may also utilize discounted cash flow model-derived pricing techniques to estimate the fair value of investment securities. Such models incorporate market-based discount rate assumptions based on observable inputs such as recent trading activity, credit data, volatility statistics, benchmark interest rate curves and other market data that are current as of the measurement date and may include certain unobservable inputs, such as assumptions of future levels of prepayment, defaults and loss severities. We review the pricing estimates obtained from the pricing sources and perform procedures to validate their reasonableness. Refer to Note 8 for further discussion of fair value measurements. We evaluate our investments designated as available-for-sale for other-than-temporary impairment ("OTTI") on at least a quarterly basis. The determination of whether a security is other-than-temporarily impaired may involve judgments and assumptions based on subjective and objective factors. When a security is impaired, an OTTI is considered to have occurred if any one of the following three conditions exists as of the financial reporting date: (i) we intend to sell the security (that is, a decision has been made to sell the security), (ii) it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis or (iii) we do not expect to recover the security's amortized cost basis, even if we do not intend to sell the security and it is not more likely than not that we will be required to sell the security. A general allowance for unidentified impairments in a portfolio of securities is not permitted. Interest Income Interest income is accrued based on the outstanding principal amount of the investment securities and their contractual terms. Premiums or discounts associated with the purchase of Agency RMBS and non-Agency MBS of high credit quality are amortized or accreted into interest income, respectively, over the projected lives of the securities, including contractual payments and estimated prepayments, using the effective interest method in accordance with ASC Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs . We estimate long-term prepayment speeds of our mortgage securities using a third-party service and market data. The third-party service provider estimates prepayment speeds using models that incorporate the forward yield curve, current mortgage rates, mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, interest rate volatility and other factors. We review the prepayment speeds estimated by the third-party service and compare the results to market consensus prepayment speeds, if available. We also consider historical prepayment speeds and current market conditions to validate the reasonableness of the third-party estimates. We review our actual and anticipated prepayment experience on at least a quarterly basis and effective yields are recalculated when differences arise between (i) our previously estimated future prepayments and (ii) actual prepayments to date and our current estimated future prepayments. If the actual and estimated future prepayment experience differs from our prior estimate of prepayments, we are required to record an adjustment in the current period to the amortization or accretion of premiums and discounts for the cumulative difference in the effective yield through the reporting date. At the time we purchase CRT securities and non-Agency MBS that are not of high credit quality, we determine an effective yield based on our estimate of the timing and amount of future cash flows and our cost basis. Our initial cash flow estimates for these investments are based on our observations of current information and events and include assumptions related to interest rates, prepayment rates and the impact of default and severity rates on the timing and amount of credit losses. On at least a quarterly basis, we review the estimated cash flows and make appropriate adjustments based on inputs and analysis received from external sources, internal models, and our judgment regarding such inputs and other factors. Any resulting changes in effective yield are recognized prospectively based on the current amortized cost of the investment adjusted for credit impairments, if any. Repurchase Agreements We finance the acquisition of securities for our investment portfolio primarily through repurchase transactions under master repurchase agreements. Pursuant to ASC Topic 860, Transfers and Servicing , we account for repurchase transactions as collateralized financing transactions, which are carried at their contractual amounts (cost), plus accrued interest. Our repurchase agreements typically have maturities of less than one year but may extend up to five years or more. Interest rates on our repurchase agreements generally correspond to one or three-month LIBOR plus or minus a fixed spread. The fair value of our repurchase agreements is assumed to equal cost as the interest rates are considered to be at market. Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivative Instruments below). We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on the balance sheet based on the value of the underlying borrowed securities as of the reporting date. Our reverse repurchase agreements typically have maturities of 30 days or less. The fair value of our reverse repurchase agreements is assumed to equal cost as the interest rates are considered to be at market. Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate, prepayment, extension and liquidity risks. The objective of our risk management strategy is to reduce fluctuations in net book value over a range of interest rate scenarios. In particular, we attempt to mitigate the risk of the cost of our variable rate liabilities increasing during a period of rising interest rates. The primary instruments that we use are interest rate swaps, options to enter into interest rate swaps ("swaptions"), U.S. Treasury securities and U.S. Treasury futures contracts. We also use forward contracts in the Agency RMBS "to-be-announced" market, or TBA securities, to invest in and finance Agency securities as well as to periodically reduce our exposure to Agency RMBS. We account for derivative instruments in accordance with ASC Topic 815, Derivatives and Hedging ("ASC 815"). ASC 815 requires an entity to recognize all derivatives as either assets or liabilities in our accompanying consolidated balance sheets and to measure those instruments at fair value. None of our derivative instruments have been designated as hedging instruments for accounting purposes under the provisions of ASC 815, consequently changes in the fair value of our derivative instruments are reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with the counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. Derivative instruments in a gain position are reported as derivative assets at fair value and derivative instruments in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Changes in fair value of derivative instruments and periodic settlements related to our derivative instruments are recorded in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized if the counterparties to these instruments fail to perform their obligations under the contracts. Our derivative agreements require that we post or receive collateral to mitigate such risk. We also attempt to minimize our risk of loss by limiting our counterparties to registered central clearing exchanges and major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Interest rate swap agreements We use interest rate swaps to economically hedge the variable cash flows associated with our borrowings made under repurchase agreements. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate based on one or three-month LIBOR ("payer swaps") with terms up to 20 years. The majority of our interest rate swaps are centrally cleared through a registered commodities exchange. We value centrally cleared interest rate swaps using the daily settlement price, or fair value, determined by the clearing exchange based on a pricing model that references observable market inputs, including LIBOR, swap rates and the forward yield curve. Our centrally cleared swaps require that we post an "initial margin" amount determined by the clearing exchange, which is generally intended to be set at a level sufficient to protect the exchange from the interest rate swap's maximum estimated single-day price movement. We also exchange daily settlements of "variation margin" based upon changes in fair value, as measured by the exchange. Pursuant to rules governing central clearing activities, we recognize variation margin settlements as a direct reduction of the carrying value of the interest rate swap asset or liability. We value non-centrally cleared swaps using a combination of third-party valuations obtained from pricing services and the swap counterparty. The third-party valuations are model-driven using observable inputs, including LIBOR, swap rates and the forward yield curve. We also consider both our own and our counterparties' nonperformance risk in estimating the fair value of our interest rate swaps. In considering the effect of nonperformance risk, we assess the impact of netting and credit enhancements, such as collateral postings and guarantees, and have concluded that our own and our counterparty risk is not significant to the overall valuation of these agreements. Interest rate swaptions We purchase interest rate swaptions to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. Interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay and receive interest rates in the future. Our interest rate swaption agreements are not subject to central clearing. The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. We estimate the fair value of interest rate swaptions using a combination of inputs from counterparty and third-party pricing models based on the fair value of the future interest rate swap that we have the option to enter into as well as the remaining length of time that we have to exercise the option, adjusted for non-performance risk, if any. The difference between the premium paid and the fair value of the swaption is reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid. If we sell or exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the cash or the fair value of the underlying interest rate swap and the premium paid. TBA securities A TBA security is a forward contract for the purchase or sale of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS to be delivered into the contract are not known until shortly before the settlement date. We may choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting TBA position, net settling the offsetting positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date (together referred to as a "dollar roll transaction"). The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to equivalent securities settling in the current month. This difference, or "price drop," is the economic equivalent of interest income on the underlying Agency securities, less an implied funding cost, over the forward settlement period (referred to as "dollar roll income"). Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. We account for TBA contracts as derivative instruments since either the TBA contracts do not settle in the shortest period of time possible or we cannot assert that it is probable at inception and throughout the term of the TBA contract that we will physically settle the contract on the settlement date. We account for TBA dollar roll transactions as a series of derivative transactions. We estimate the fair value of TBA securities based on similar methods used to value our Agency RMBS securities. U.S. Treasury securities We use U.S. Treasury securities and U.S. Treasury futures contracts to mitigate the potential impact of changes in interest rates on the performance of our portfolio. We borrow U.S. Treasury securities under reverse repurchase agreements to cover short sales of U.S. Treasury securities. We account for these as securities borrowing transactions and recognize an obligation to return the borrowed securities at fair value on our accompanying consolidated balance sheets based on the value of the underlying U.S. Treasury security as of the reporting date. Gains and losses associated with U.S. Treasury securities and U.S. Treasury futures contracts are recognized in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Loss Contingencies We evaluate the existence of any pending or threatened litigation or other potential claims against the Company in accordance with ASC Topic 450, Contingencies, which requires that we assess the likelihood and range of potential outcomes of any such matters. We are the defendant in three stockholder derivative lawsuits alleging that certain of our current and former directors and officers breached fiduciary duties and wasted corporate assets relating to past renewals of the management agreement with our former external manager and the internalization of our management on July 1, 2016. Although the outcomes of these cases cannot be predicted with certainty, we do not believe that these cases have merit or will result in a material liability, and, as of March 31, 2019 , we did not accrue a loss contingency related to these matters. Recent Accounting Pronouncements We consider the applicability and impact of all Accounting Standards Updates ("ASUs") issued by the Financial Accounting Standards Board. ASUs not listed below were determined to be either not applicable, are not expected to have a significant impact on our consolidated financial statements when adopted or did not have a significant impact on our consolidated financial statements upon adoption. ASU 2016-13, Financial Instruments - Credit Losses (Topic 326):

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investment Securities	3 years and ≤ 5 years 18,438 18,225 3.85% 3.35% 5,518 5,586 3.35% 2.73% > 5 years and ≤10 years 74,329 74,354 3.89% 3.29% 72,503 73,588 3.92% 3.37% > 10 years 51 50 3.78% 4.12% 4,576 4,679 3.57% 3.30% Total $ 95,270 $ 95,090 3.88% 3.29% $ 84,287 $ 85,569 3.86% 3.31% The following table presents the gross unrealized loss and fair values of securities classified as available-for-sale by length of time that such securities have been in a continuous unrealized loss position as of March 31, 2019 and December 31, 2018 (in millions): Unrealized Loss Position For Less than 12 Months 12 Months or More Total Securities Classified as Available-for-Sale Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss March 31, 2019 $ 108 $ (1 ) $ 20,119 $ (567 ) $ 20,227 $ (568 ) December 31, 2018 $ 4,783 $ (72 ) $ 18,231 $ (878 ) $ 23,014 $ (950 ) We did not recognize OTTI charges on our investment securities during the periods presented on our consolidated statements of operations. As of the end of each respective reporting period, a decision had not been made to sell securities in an unrealized loss position and we did not believe it was more likely than not that we would be required to sell such securities before recovery of their amortized cost basis. The unrealized losses on our securities were not due to credit losses given the GSE or U.S. Government agency guarantees, but rather were due to changes in interest rates and prepayment expectations. However, as we continue to actively manage our portfolio, we may recognize additional realized losses on our investment securities upon selecting specific securities to sell. Gains and Losses on Sale of Investment Securities The following table is a summary of our net gain (loss) from the sale of investment securities for the three months ended March 31, 2019 and 2018 by investment classification of accounting (in millions): Three Months Ended March 31, 2019 2018 Investment Securities Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale Securities 2 Fair Value Option Securities Total Investment securities sold, at cost $ (339 ) $ (4,562 ) $ (4,901 ) $ (387 ) $ (1,003 ) $ (1,390 ) Proceeds from investment securities sold 1 335 4,626 4,961 388 1,000 1,388 Net gain (loss) on sale of investment securities $ (4 ) $ 64 $ 60 $ 1 $ (3 ) $ (2 ) Gross gain on sale of investment securities $ — $ 66 $ 66 $ 3 $ 7 $ 10 Gross loss on sale of investment securities (4 ) (2 ) (6 ) (2 ) (10 ) (12 ) Net gain (loss) on sale of investment securities $ (4 ) $ 64 $ 60 $ 1 $ (3 ) $ (2 ) ________________________________ 1. Proceeds include cash received during the period, plus receivable for investment securities sold during the period as of period end. 2. See Note 10 for a summary of changes in accumulated OCI. Consolidated Variable Interest Entities As of March 31, 2019 and December 31, 2018" id="sjs-B4">Investment Securities As of March 31, 2019 and December 31, 2018 , our investment portfolio consisted of $95.3 billion and $84.3 billion of investment securities, at fair value, respectively, and $7.0 billion and $7.3 billion of TBA securities, at fair value, respectively. Our TBA position is reported at its net carrying value of $70 million and $70 million as of March 31, 2019 and December 31, 2018 , respectively, in derivative assets / (liabilities) on our accompanying consolidated balance sheets. The net carrying value of our TBA position represents the difference between the fair value of the underlying Agency security in the TBA contract and the cost basis or the forward price to be paid or received for the underlying Agency security. As of March 31, 2019 and December 31, 2018 , our investment securities had a net unamortized premium balance of $3.0 billion and $2.9 billion , respectively. The following tables summarize our investment securities as of March 31, 2019 and December 31, 2018 , excluding TBA securities, (dollars in millions). Details of our TBA securities as of each of the respective dates are included in Note 6 . March 31, 2019 December 31, 2018 Investment Securities Amortized Cost Fair Value Amortized Fair Value Agency RMBS: Fixed rate $ 92,374 $ 92,502 $ 83,047 $ 81,753 Adjustable rate 199 201 212 213 CMO 555 555 588 583 Interest-only and principal-only strips 166 179 172 178 Multifamily 31 32 — — Total Agency RMBS 93,325 93,469 84,019 82,727 Non-Agency RMBS 313 319 264 266 CMBS 343 353 280 282 CRT securities 1,109 1,129 1,006 1,012 Total investment securities $ 95,090 $ 95,270 $ 85,569 $ 84,287 March 31, 2019 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 16,709 $ 5,493 $ 23 $ 6 $ — $ — $ 22,231 Unamortized discount (11 ) (2 ) — — — — (13 ) Unamortized premium 849 325 — — — — 1,174 Amortized cost 17,547 5,816 23 6 — — 23,392 Gross unrealized gains 19 5 1 — — — 25 Gross unrealized losses (402 ) (166 ) — — — — (568 ) Total available-for-sale securities, at fair value 17,164 5,655 24 6 — — 22,849 Securities remeasured at fair value through earnings: Par value 42,546 25,501 — 317 409 1,087 69,860 Unamortized discount (74 ) (6 ) — (11 ) (70 ) (13 ) (174 ) Unamortized premium 1,138 834 — — 5 35 2,012 Amortized cost 43,610 26,329 — 306 344 1,109 71,698 Gross unrealized gains 620 340 — 7 10 22 999 Gross unrealized losses (172 ) (101 ) — — (1 ) (2 ) (276 ) Total securities remeasured at fair value through earnings 44,058 26,568 — 313 353 1,129 72,421 Total securities, at fair value $ 61,222 $ 32,223 $ 24 $ 319 $ 353 $ 1,129 $ 95,270 Weighted average coupon as of March 31, 2019 3.83 % 3.92 % 3.72 % 3.86 % 4.65 % 5.69 % 3.88 % Weighted average yield as of March 31, 2019 1 3.24 % 3.30 % 2.06 % 4.22 % 4.61 % 4.75 % 3.29 % ________________________________ 1. Incorporates a weighted average future constant prepayment rate assumption of 10.5% based on forward rates as of March 31, 2019 . December 31, 2018 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 17,591 $ 5,673 $ 25 $ 6 $ — $ — $ 23,295 Unamortized discount (10 ) (2 ) — — — — (12 ) Unamortized premium 912 343 — — — — 1,255 Amortized cost 18,493 6,014 25 6 — — 24,538 Gross unrealized gains 4 2 1 — — — 7 Gross unrealized losses (686 ) (264 ) — — — — (950 ) Total available-for-sale securities, at fair value 17,811 5,752 26 6 — — 23,595 Securities remeasured at fair value through earnings: Par value 39,453 18,428 — 268 281 968 59,398 Unamortized discount (78 ) (9 ) — (10 ) (6 ) — (103 ) Unamortized premium 1,055 638 — — 5 38 1,736 Amortized cost 40,430 19,057 — 258 280 1,006 61,031 Gross unrealized gains 223 57 — 2 3 18 303 Gross unrealized losses (386 ) (243 ) — — (1 ) (12 ) (642 ) Total securities remeasured at fair value through earnings 40,267 18,871 — 260 282 1,012 60,692 Total securities, at fair value $ 58,078 $ 24,623 $ 26 $ 266 $ 282 $ 1,012 $ 84,287 Weighted average coupon as of December 31, 2018 3.82 % 3.87 % 3.37 % 3.83 % 4.58 % 5.86 % 3.86 % Weighted average yield as of December 31, 2018 1 3.28 % 3.28 % 2.04 % 4.22 % 4.68 % 5.16 % 3.31 % ________________________________ 1. Incorporates a weighted average future constant prepayment rate assumption of 7.9% based on forward rates as of December 31, 2018 . As of March 31, 2019 and December 31, 2018 , our investments in CRT and non-Agency securities had the following credit ratings: March 31, 2019 December 31, 2018 CRT and Non-Agency Security Credit Ratings 1 CRT RMBS CMBS CRT RMBS CMBS AAA $ — $ 156 $ 62 $ — $ 160 $ 52 AA — 42 190 — 17 152 A 17 45 33 17 33 15 BBB 54 63 58 25 43 53 BB 412 8 10 492 8 10 B 600 2 — 453 2 — Not Rated 46 3 — 25 3 — Total $ 1,129 $ 319 $ 353 $ 1,012 $ 266 $ 282 ________________________________ 1. Represents the lowest of Standard and Poor's ("S&P"), Moody's, Fitch, DBRS, Kroll Bond Rating Agency ("KBRA") and Morningstar credit ratings, stated in terms of the S&P equivalent rating as of each date. Our CRT securities reference the performance of loans underlying Agency RMBS issued by Fannie Mae or Freddie Mac, which were subject to their underwriting standards. As of March 31, 2019 , our CRT securities had floating and fixed rate coupons ranging from 3.0% to 8.8% , referenced to loans originated between 2011 and 2018 with weighted average coupons ranging from 3.7% to 4.9% . As of December 31, 2018 , our CRT securities had floating rate coupons ranging from 3.9% to 9.5% , referenced to loans originated between 2011 and 2018 with weighted average coupons ranging from 3.8% to 4.8% . The actual maturities of our investment securities are generally shorter than their stated contractual maturities. The actual maturities of our Agency and high credit quality non-Agency RMBS are primarily affected by principal prepayments and to a lesser degree the contractual lives of the underlying mortgages and periodic contractual principal repayments. The actual maturities of our credit-oriented investments are primarily impacted by their contractual lives and default and loss recovery rates. As of March 31, 2019 and December 31, 2018 , the weighted average expected constant prepayment rate ("CPR") over the remaining life of our Agency and high credit quality non-Agency RMBS investment portfolio was 10.5% and 7.9% , respectively. Our estimates can differ materially for different securities and thus our individual holdings have a wide range of projected CPRs. The following table summarizes our investments as of March 31, 2019 and December 31, 2018 according to their estimated weighted average life classification (dollars in millions): March 31, 2019 December 31, 2018 Estimated Weighted Average Life of Investment Securities Fair Value Amortized Cost Weighted Average Coupon Weighted Average Yield Fair Value Amortized Cost Weighted Average Coupon Weighted Average Yield ≥ 1 year and ≤ 3 years $ 2,452 $ 2,461 3.94% 2.83% $ 1,690 $ 1,716 3.99% 2.64% > 3 years and ≤ 5 years 18,438 18,225 3.85% 3.35% 5,518 5,586 3.35% 2.73% > 5 years and ≤10 years 74,329 74,354 3.89% 3.29% 72,503 73,588 3.92% 3.37% > 10 years 51 50 3.78% 4.12% 4,576 4,679 3.57% 3.30% Total $ 95,270 $ 95,090 3.88% 3.29% $ 84,287 $ 85,569 3.86% 3.31% The following table presents the gross unrealized loss and fair values of securities classified as available-for-sale by length of time that such securities have been in a continuous unrealized loss position as of March 31, 2019 and December 31, 2018 (in millions): Unrealized Loss Position For Less than 12 Months 12 Months or More Total Securities Classified as Available-for-Sale Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss March 31, 2019 $ 108 $ (1 ) $ 20,119 $ (567 ) $ 20,227 $ (568 ) December 31, 2018 $ 4,783 $ (72 ) $ 18,231 $ (878 ) $ 23,014 $ (950 ) We did not recognize OTTI charges on our investment securities during the periods presented on our consolidated statements of operations. As of the end of each respective reporting period, a decision had not been made to sell securities in an unrealized loss position and we did not believe it was more likely than not that we would be required to sell such securities before recovery of their amortized cost basis. The unrealized losses on our securities were not due to credit losses given the GSE or U.S. Government agency guarantees, but rather were due to changes in interest rates and prepayment expectations. However, as we continue to actively manage our portfolio, we may recognize additional realized losses on our investment securities upon selecting specific securities to sell. Gains and Losses on Sale of Investment Securities The following table is a summary of our net gain (loss) from the sale of investment securities for the three months ended March 31, 2019 and 2018 by investment classification of accounting (in millions): Three Months Ended March 31, 2019 2018 Investment Securities Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale Securities 2 Fair Value Option Securities Total Investment securities sold, at cost $ (339 ) $ (4,562 ) $ (4,901 ) $ (387 ) $ (1,003 ) $ (1,390 ) Proceeds from investment securities sold 1 335 4,626 4,961 388 1,000 1,388 Net gain (loss) on sale of investment securities $ (4 ) $ 64 $ 60 $ 1 $ (3 ) $ (2 ) Gross gain on sale of investment securities $ — $ 66 $ 66 $ 3 $ 7 $ 10 Gross loss on sale of investment securities (4 ) (2 ) (6 ) (2 ) (10 ) (12 ) Net gain (loss) on sale of investment securities $ (4 ) $ 64 $ 60 $ 1 $ (3 ) $ (2 ) ________________________________ 1. Proceeds include cash received during the period, plus receivable for investment securities sold during the period as of period end. 2. See Note 10 for a summary of changes in accumulated OCI. Consolidated Variable Interest Entities As of March 31, 2019 and December 31, 2018

Repurchase Agreements And Rever

Repurchase Agreements And Reverse Repurchase Agreements	3 Months Ended
	Mar. 31, 2019
Disclosure of Repurchase Agreements [Abstract]
Repurchase Agreements And Other Debt	1 to ≤ 3 months 26,690 2.66 % 65 20,991 2.57 % 56 > 3 to ≤ 6 months 2,181 2.67 % 125 2,218 2.65 % 167 > 6 to ≤ 9 months 2,450 2.68 % 204 200 3.19 % 208 > 9 to ≤ 12 months 7,554 2.75 % 288 950 2.80 % 279 > 12 to ≤ 24 months 1,825 2.97 % 516 2,200 2.91 % 438 > 24 to ≤ 36 months 1,000 2.67 % 1,044 625 3.11 % 776 Total Agency repo 86,324 2.82 % 81 75,717 2.79 % 49 U.S. Treasury repo: > 1 day to ≤ 1 month 361 2.91 % 1 — — % — Total $ 86,685 2.82 % 81 $ 75,717 2.79 % 49 As of March 31, 2019 and December 31, 2018 , $18.7 billion and $19.5 billion , respectively, of our repurchase agreements had a remaining maturity of one business day and none of our repurchase agreements were due on demand. As of March 31, 2019 , we had $10.7 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 85 days and a weighted average interest rate of 2.55% . As of December 31, 2018 we had $10.7 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 9 days and a weighted average interest rate of 2.90% . As of March 31, 2019 and December 31, 2018 , 41% and 35% , respectively, of our repurchase agreement funding was sourced through our wholly-owned captive broker-dealer subsidiary, Bethesda Securities, LLC ("BES"). Amounts sourced through BES include funding from the General Collateral Finance Repo service ("GCF Repo") offered by the Fixed Income Clearing Corporation ("FICC"), which totaled 40% and 33% of our repurchase agreement funding outstanding as of March 31, 2019 and December 31, 2018 , respectively. Reverse Repurchase Agreements As of March 31, 2019 and December 31, 2018 , we had $20.4 billion and $21.8 billion , respectively, of reverse repurchase agreements outstanding used primarily to borrow securities to cover short sales of U.S. Treasury securities, for which we had associated obligations to return borrowed securities at fair value of $19.3 billion and $21.4 billion , respectively. As of March 31, 2019 and December 31, 2018 , $5.6 billion and $4.5 billion , respectively, of our reverse repurchase agreements were with the FICC sourced through BES. Other Debt As of March 31, 2019 and December 31, 2018 , we had debt of consolidated VIEs, at fair value, of $266 million and $275 million , respectively, which had a weighted average interest rate of LIBOR plus 41 and 40 basis points, respectively, and an estimated weighted average life of 5.9 years and 6.1" id="sjs-B4">Repurchase Agreements and Other Debt Repurchase Agreements We pledge our securities as collateral under our borrowings structured as repurchase agreements with financial institutions. Interest rates on our borrowings are generally based on LIBOR plus or minus a margin and amounts available to be borrowed are dependent upon the fair value of the securities pledged as collateral, which fluctuates with changes in interest rates, type of security and liquidity conditions within the banking, mortgage finance and real estate industries. If the fair value of our pledged securities declines, lenders will typically require us to post additional collateral or pay down borrowings to re-establish agreed upon collateral requirements, referred to as "margin calls." Similarly, if the fair value of our pledged securities increases, lenders may release collateral back to us. As of March 31, 2019 , we had met all margin call requirements. For additional information regarding our pledged assets, please refer to Note 7 . As of March 31, 2019 and December 31, 2018 , we had $86.7 billion and $75.7 billion , respectively, of repurchase agreements outstanding used to fund our investment portfolio and temporary holdings of U.S. Treasury securities. The terms and conditions of our repurchase agreements are typically negotiated on a transaction-by-transaction basis. Our repurchase agreements with original maturities greater than one year have floating interest rates based on an index plus or minus a fixed spread. The following table summarizes our borrowings under repurchase agreements by their remaining maturities as of March 31, 2019 and December 31, 2018 (dollars in millions): March 31, 2019 December 31, 2018 Remaining Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Agency repo: ≤ 1 month $ 44,624 2.94 % 8 $ 48,533 2.88 % 9 > 1 to ≤ 3 months 26,690 2.66 % 65 20,991 2.57 % 56 > 3 to ≤ 6 months 2,181 2.67 % 125 2,218 2.65 % 167 > 6 to ≤ 9 months 2,450 2.68 % 204 200 3.19 % 208 > 9 to ≤ 12 months 7,554 2.75 % 288 950 2.80 % 279 > 12 to ≤ 24 months 1,825 2.97 % 516 2,200 2.91 % 438 > 24 to ≤ 36 months 1,000 2.67 % 1,044 625 3.11 % 776 Total Agency repo 86,324 2.82 % 81 75,717 2.79 % 49 U.S. Treasury repo: > 1 day to ≤ 1 month 361 2.91 % 1 — — % — Total $ 86,685 2.82 % 81 $ 75,717 2.79 % 49 As of March 31, 2019 and December 31, 2018 , $18.7 billion and $19.5 billion , respectively, of our repurchase agreements had a remaining maturity of one business day and none of our repurchase agreements were due on demand. As of March 31, 2019 , we had $10.7 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 85 days and a weighted average interest rate of 2.55% . As of December 31, 2018 we had $10.7 billion of forward commitments to enter into repurchase agreements, with a weighted average forward start date of 9 days and a weighted average interest rate of 2.90% . As of March 31, 2019 and December 31, 2018 , 41% and 35% , respectively, of our repurchase agreement funding was sourced through our wholly-owned captive broker-dealer subsidiary, Bethesda Securities, LLC ("BES"). Amounts sourced through BES include funding from the General Collateral Finance Repo service ("GCF Repo") offered by the Fixed Income Clearing Corporation ("FICC"), which totaled 40% and 33% of our repurchase agreement funding outstanding as of March 31, 2019 and December 31, 2018 , respectively. Reverse Repurchase Agreements As of March 31, 2019 and December 31, 2018 , we had $20.4 billion and $21.8 billion , respectively, of reverse repurchase agreements outstanding used primarily to borrow securities to cover short sales of U.S. Treasury securities, for which we had associated obligations to return borrowed securities at fair value of $19.3 billion and $21.4 billion , respectively. As of March 31, 2019 and December 31, 2018 , $5.6 billion and $4.5 billion , respectively, of our reverse repurchase agreements were with the FICC sourced through BES. Other Debt As of March 31, 2019 and December 31, 2018 , we had debt of consolidated VIEs, at fair value, of $266 million and $275 million , respectively, which had a weighted average interest rate of LIBOR plus 41 and 40 basis points, respectively, and an estimated weighted average life of 5.9 years and 6.1

Derivative and Other Hedging In

Derivative and Other Hedging Instruments	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
US Government Futures Securities [Table Text Block]	U.S. Treasury Futures March 31, 2019 December 31, 2018 Maturity Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 10 years $ (1,650 ) $ (2,019 ) $ (2,050 ) $ (31 ) $ (1,650 ) $ (1,969 ) $ (2,013 ) $ (44 ) ________________________________ 1.
Derivative and Other Hedging Instruments	Derivative and Other Hedging Instruments We hedge a portion of our interest rate risk primarily utilizing interest rate swaps, interest rate swaptions, U.S. Treasury securities and U.S. Treasury futures contracts. We utilize TBA securities primarily as a means of investing in the Agency securities market. For additional information regarding our derivative instruments and our overall risk management strategy, please refer to the discussion of derivative and other hedging instruments in Note 3 . Derivative and Other Hedging Instrument Assets (Liabilities), at Fair Value The table below summarizes fair value information about our derivative and other hedging instrument assets/(liabilities) as of March 31, 2019 and December 31, 2018 (in millions): Derivative and Other Hedging Instruments Balance Sheet Location March 31, 2019 December 31, 2018 Interest rate swaps Derivative assets, at fair value $ 151 $ 126 Swaptions Derivative assets, at fair value 11 37 TBA securities Derivative assets, at fair value 91 110 Total derivative assets, at fair value $ 253 $ 273 Interest rate swaps Derivative liabilities, at fair value $ (1 ) $ — TBA securities Derivative liabilities, at fair value (21 ) (40 ) U.S. Treasury futures - short Derivative liabilities, at fair value (31 ) (44 ) Total derivative liabilities, at fair value $ (53 ) $ (84 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ 121 $ 46 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (19,275 ) (21,431 ) Total U.S. Treasury securities, net at fair value $ (19,154 ) $ (21,385 ) The following tables summarize certain characteristics of our derivative and other hedging instruments outstanding as of March 31, 2019 and December 31, 2018 (dollars in millions): March 31, 2019 December 31, 2018 Interest Rate Swaps Notional 1 Average Rate 2 Average Average Notional 1 Average Rate 2 Average Average ≤ 3 years $ 20,900 1.71% 2.69% 1.2 $ 19,900 1.63% 2.62% 1.3 > 3 to ≤ 5 years 9,425 2.11% 2.69% 3.7 8,425 2.06% 2.61% 4.0 > 5 to ≤ 7 years 6,225 2.38% 2.67% 5.8 7,875 2.66% 2.66% 6.1 > 7 to ≤ 10 years 9,700 2.30% 2.68% 8.6 10,550 2.36% 2.64% 8.8 > 10 years 1,925 2.30% 2.69% 13.2 4,875 2.77% 2.63% 11.6 Total $ 48,175 2.01% 2.69% 4.3 $ 51,625 2.11% 2.63% 5.0 ________________________________ 1. As of March 31, 2019 and December 31, 2018 , notional amount includes forward starting swaps of $4.0 billion and $5.7 billion , respectively, with an average forward start date of 0.2 and 0.5 years, respectively. 2. Average fixed pay rate includes forward starting swaps. Excluding forward starting swaps, the average fixed pay rate was 1.96% and 1.98% as of March 31, 2019 and December 31, 2018 , respectively. Swaptions Option Underlying Payer Swap Current Option Expiration Date Cost Basis Fair Value Average Months to Current Option Expiration Date 1 Notional Amount Average Fixed Pay Rate Average Receive Rate (LIBOR) Average Term (Years) March 31, 2019 ≤ 1 year $ 71 $ 5 4 $ 2,050 2.98% 3M 7.0 > 1 year ≤ 2 years 18 6 15 500 2.78% 3M 10.0 Total $ 89 $ 11 7 $ 2,550 2.94% 3M 7.6 December 31, 2018 ≤ 1 year $ 80 $ 23 4 $ 3,000 2.96% 3M 7.0 > 1 year ≤ 2 years 18 14 18 500 2.78% 3M 10.0 Total $ 98 $ 37 6 $ 3,500 2.93% 3M 7.4 ________________________________ 1. As of March 31, 2019 and December 31, 2018 , ≤ 1 year notional amount includes $700 million of Bermudan swaptions where the options may be exercised on predetermined dates up to their final exercise date, which is six months prior to the underlying swaps' maturity date. U.S. Treasury Securities March 31, 2019 December 31, 2018 Maturity Face Amount (Short) Cost Basis 1 Fair Value Face Amount (Short) Cost Basis 1 Fair Value 5 years $ 120 $ 120 $ 121 $ (703 ) $ (706 ) $ (713 ) 7 years (12,990 ) (12,976 ) (13,285 ) (14,357 ) (14,325 ) (14,410 ) 10 years (5,745 ) (5,810 ) (5,990 ) (6,240 ) (6,224 ) (6,262 ) Total U.S. Treasury securities $ (18,615 ) $ (18,666 ) $ (19,154 ) $ (21,300 ) $ (21,255 ) $ (21,385 ) ________________________________ 1. As of March 31, 2019 and December 31, 2018 , U.S. Treasury securities had a weighted average yield of 2.66% . U.S. Treasury Futures March 31, 2019 December 31, 2018 Maturity Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 10 years $ (1,650 ) $ (2,019 ) $ (2,050 ) $ (31 ) $ (1,650 ) $ (1,969 ) $ (2,013 ) $ (44 ) ________________________________ 1. Net carrying value represents the difference between the fair market value and the cost basis (or the forward price to be paid/(received) for the underlying U.S. Treasury security) of the U.S. Treasury futures contract as of period-end and is reported in derivative assets/(liabilities), at fair value in our consolidated balance sheets. March 31, 2019 December 31, 2018 TBA Securities by Coupon Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 15-Year TBA securities: 3.0% $ 327 $ 328 $ 329 $ 1 $ 567 $ 557 $ 566 $ 9 3.5% 1,969 1,996 2,013 17 1,706 1,708 1,726 18 4.0% 1,083 1,108 1,115 7 1,350 1,370 1,381 11 Total 15-Year TBA securities 3,379 3,432 3,457 25 3,623 3,635 3,673 38 30-Year TBA securities: 3.0% 903 886 899 13 1,028 981 1,003 22 3.5% 3,084 3,095 3,125 30 (2,979 ) (2,943 ) (2,977 ) (34 ) 4.0% (3,148 ) (3,222 ) (3,238 ) (16 ) 3,030 3,073 3,089 16 ≥ 4.5% 2,604 2,694 2,712 18 2,450 2,506 2,534 28 Total 30-Year TBA securities, net 3,443 3,453 3,498 45 3,529 3,617 3,649 32 Total TBA securities, net $ 6,822 $ 6,885 $ 6,955 $ 70 $ 7,152 $ 7,252 $ 7,322 $ 70 ________________________________ 1. Net carrying value represents the difference between the fair market value and the cost basis (or the forward price to be paid/(received) for the underlying Agency security) of the TBA contract as of period-end and is reported in derivative assets/(liabilities), at fair value in our consolidated balance sheets. Gain (Loss) From Derivative Instruments and Other Securities, Net The following table summarizes changes in our derivative and other hedge portfolio and their effect on our consolidated statements of comprehensive income for the three months ended March 31, 2019 and 2018 (in millions): Derivative and Other Hedging Instruments Beginning Notional Amount Additions Settlement, Termination, Expiration or Exercise Ending Notional Amount Gain/(Loss) on Derivative Instruments and Other Securities, Net 1 Three months ended March 31, 2019: TBA securities, net $ 7,152 18,442 (18,772 ) $ 6,822 $ 83 Interest rate swaps $ 51,625 5,350 (8,800 ) $ 48,175 (596 ) Payer swaptions $ 3,500 — (950 ) $ 2,550 (27 ) U.S. Treasury securities - short position $ (21,345 ) (4,770 ) 7,380 $ (18,735 ) (425 ) U.S. Treasury securities - long position $ 45 405 (330 ) $ 120 — U.S. Treasury futures contracts - short position $ (1,650 ) (1,650 ) 1,650 $ (1,650 ) (31 ) $ (996 ) Three months ended March 31, 2018: TBA securities, net $ 15,474 43,669 (45,507 ) $ 13,636 $ (292 ) Interest rate swaps $ 43,700 3,150 (1,600 ) $ 45,250 663 Payer swaptions $ 6,650 1,100 (1,000 ) $ 6,750 91 U.S. Treasury securities - short position $ (10,699 ) (662 ) 563 $ (10,798 ) 212 U.S. Treasury securities - long position $ — 959 (734 ) $ 225 — U.S. Treasury futures contracts - short position $ (2,910 ) (2,909 ) 3,439 $ (2,380 ) 62 $ 736 ________________________________ 1.

Pledged Assets

Pledged Assets	3 Months Ended
	Mar. 31, 2019
Pledged Assets [Abstract]
Pledged Assets	30 and ≤ 60 days 10,792 10,758 34 14,586 14,810 46 > 60 and ≤ 90 days 17,282 17,267 53 7,770 7,843 24 > 90 days 15,945 16,108 48 6,882 7,079 21 Total $ 89,966 $ 89,806 $ 278 $ 79,182 $ 80,386 $ 247 ________________________________ 1. Includes $161 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2019 and December 31, 2018 , respectively. 2. Excludes $496 million and $437 million of repledged U.S. Treasury securities received as collateral from counterparties as of March 31, 2019 and December 31, 2018 , repsectively. Assets Pledged from Counterparties As of March 31, 2019 and December 31, 2018 , we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions). March 31, 2019 December 31, 2018 Assets Pledged to AGNC 1 Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total U.S. Treasury securities - fair value $ 20,400 $ 10 $ 30 $ 20,440 $ 21,876 $ 35 $ 37 $ 21,948 Cash — 49 — 49 — 129 — 129 Total $ 20,400 $ 59 $ 30 $ 20,489 $ 21,876 $ 164 $ 37 $ 22,077 ________________________________ 1. Includes $496 million and $437 million of repledged U.S. Treasury securities received as collateral from counterparties as of March 31, 2019 and December 31, 2018 , respectively. U.S Treasury securities received as collateral under our reverse repurchase agreements for which we use to cover short sales of U.S. Treasury securities are accounted for as securities borrowing transactions. We recognize a corresponding obligation to return the borrowed securities at fair value on the accompanying consolidated balance sheets based on the value of the underlying borrowed securities as of the reporting date. Cash collateral received is recognized in cash and cash equivalents with a corresponding amount recognized in accounts payable and other accrued liabilities on the accompanying consolidated balance sheets. Offsetting Assets and Liabilities Certain of our repurchase agreements and derivative transactions are governed by underlying agreements that generally provide for a right of setoff under master netting arrangements (or similar agreements), including in the event of default or in the event of bankruptcy of either party to the transactions. We present our assets and liabilities subject to such arrangements on a gross basis in our consolidated balance sheets. The following tables present information about our assets and liabilities that are subject to master netting arrangements and can potentially be offset on our consolidated balance sheets as of March 31, 2019 and December 31, 2018 (in millions): Offsetting of Financial and Derivative Assets Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Assets Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Net Amount Financial Instruments Collateral Received 2 March 31, 2019 Interest rate swap and swaption agreements, at fair value 1 $ 162 $ — $ 162 $ (1 ) $ (59 ) $ 102 TBA securities, at fair value 91 — 91 (21 ) — 70 Receivable under reverse repurchase agreements 20,430 — 20,430 (17,353 ) (3,072 ) 5 Total $ 20,683 $ — $ 20,683 $ (17,375 ) $ (3,131 ) $ 177 December 31, 2018 Interest rate swap and swaption agreements, at fair value 1 $ 163 $ — $ 163 $ — $ (158 ) $ 5 TBA securities, at fair value 110 — 110 (40 ) — 70 Receivable under reverse repurchase agreements 21,813 — 21,813 (17,236 ) (4,575 ) 2 Total $ 22,086 $ — $ 22,086 $ (17,276 ) $ (4,733 ) $ 77 Offsetting of Financial and Derivative Liabilities Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Liabilities Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Net Amount Financial Instruments Collateral Pledged 2 March 31, 2019 Interest rate swap agreements, at fair value 1 $ 1 $ — $ 1 $ (1 ) $ — $ — TBA securities, at fair value 21 — 21 (21 ) — — Repurchase agreements 86,685 — 86,685 (17,353 ) (69,332 ) — Total $ 86,707 $ — $ 86,707 $ (17,375 ) $ (69,332 ) $ — December 31, 2018 Interest rate swap agreements, at fair value 1 $ — $ — $ — $ — $ — $ — TBA securities, at fair value 40 — 40 (40 ) — — Repurchase agreements 75,717 — 75,717 (17,236 ) (58,481 ) — Total $ 75,757 $ — $ 75,757 $ (17,276 ) $ (58,481 ) $ — ________________________________ 1. Reported under derivative assets / liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 6 for a reconciliation of derivative assets / liabilities, at fair value to their sub-components. 2." id="sjs-B4">Pledged Assets Our funding agreements require us to fully collateralize our obligations under the agreements based upon our counterparties' collateral requirements and their determination of the fair value of the securities pledged as collateral, which fluctuates with changes in interest rates, credit quality and liquidity conditions within the investment banking, mortgage finance and real estate industries. Our derivative contracts similarly require us to fully collateralize our obligations under such agreements, which will vary over time based on similar factors as well as our counterparties' determination of the value of the derivative contract. We are typically required to post initial margin upon execution of derivative transactions, such as under our interest rate swap agreements and TBA contracts, and subsequently post or receive variation margin based on daily fluctuations in fair value. Our prime brokerage agreements, pursuant to which we receive custody and settlement services, and the clearing organizations utilized by our wholly-owned captive broker-dealer subsidiary, Bethesda Securities, LLC, also require that we post minimum daily clearing deposits. If we breach our collateral requirements, we will be required to fully settle our obligations under the agreements, which could include a forced liquidation of our pledged collateral. Our counterparties also apply a "haircut" to our pledged collateral, which means our collateral is valued at slightly less than market value and limits the amount we can borrow against our securities. This haircut reflects the underlying risk of the specific collateral and protects our counterparty against a change in its value. Our agreements do not specify the haircut; rather haircuts are determined on an individual transaction basis. Consequently, our funding agreements and derivative contracts expose us to credit risk relating to potential losses that could be recognized if our counterparties fail to perform their obligations under such agreements. We minimize this risk by limiting our counterparties to major financial institutions with acceptable credit ratings or to registered clearinghouses and U.S. government agencies, and we monitor our positions with individual counterparties. In the event of a default by a counterparty, we may have difficulty obtaining our assets pledged as collateral to such counterparty and may not receive payments 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, clearinghouse guarantee funds and other resources that are available in the event of a clearing member default. As of March 31, 2019 , our maximum amount at risk with any counterparty other than the Fixed Income Clearing Corporation related to our repurchase agreements was less than 4% of our tangible stockholders' equity. As of March 31, 2019 , approximately 7% of our tangible stockholder's equity was at risk with the Fixed Income Clearing Corporation. Equity at risk is defined as the net carrying value of 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. Our International Swaps and Derivatives Association ("ISDA") Master Agreements contain a cross default provision under which a default under the terms of certain of our other indebtedness in excess of certain thresholds causes an event of default under the ISDA Master Agreement. Threshold amounts vary by lender. Following an event of default, we could be required to settle our obligations under the agreements. Additionally, under certain of our ISDA Master Agreements, we could be required to settle our obligations under the agreements if we fail to maintain certain minimum stockholders' equity thresholds or our REIT status or if we fail to comply with limits on our leverage up to certain specified levels. As of March 31, 2019 , 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. Assets Pledged to Counterparties The following tables summarize our assets pledged as collateral under our funding, derivative and prime broker agreements by type, including securities pledged related to securities sold but not yet settled, as of March 31, 2019 and December 31, 2018 (in millions): March 31, 2019 Assets Pledged to Counterparties 1 Repurchase Agreements 2 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements 3 Total Agency RMBS - fair value $ 89,779 $ 425 $ 174 $ 118 $ 90,496 CRT - fair value 142 — — — 142 Non-Agency - fair value 45 — — — 45 U.S. Treasury securities - fair value 617 — — — 617 Accrued interest on pledged securities 278 1 1 — 280 Restricted cash and cash equivalents 75 — 442 — 517 Total $ 90,936 $ 426 $ 617 $ 118 $ 92,097 December 31, 2018 Assets Pledged to Counterparties 1 Repurchase Agreements 2 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements 3 Total Agency RMBS - fair value $ 78,997 $ 436 $ 174 $ 133 $ 79,740 CRT - fair value 141 — — — 141 Non-Agency - fair value 45 — — — 45 U.S. Treasury securities - fair value 437 — — — 437 Accrued interest on pledged securities 246 1 1 — 248 Restricted cash and cash equivalents 77 — 522 — 599 Total $ 79,943 $ 437 $ 697 $ 133 $ 81,210 ________________________________ 1. Includes repledged assets received as collateral from counterparties. 2. Includes $161 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2019 and December 31, 2018 , respectively. 3. Includes margin for TBAs cleared through prime brokers and other clearing deposits. 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 Note 4 for additional information regarding our consolidated VIEs. The following table summarizes our securities pledged as collateral under our repurchase agreements by the remaining maturity of our borrowings, including securities pledged related to sold but not yet settled securities, as of March 31, 2019 and December 31, 2018 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 5 . March 31, 2019 December 31, 2018 Securities Pledged by Remaining Maturity of Repurchase Agreements 1,2 Fair Value of Pledged Securities Amortized Cost of Pledged Securities Accrued Interest on Pledged Securities Fair Value of Pledged Securities Amortized Cost of Pledged Securities Accrued Interest on Pledged Securities ≤ 30 days $ 45,947 $ 45,673 $ 143 $ 49,944 $ 50,654 $ 156 > 30 and ≤ 60 days 10,792 10,758 34 14,586 14,810 46 > 60 and ≤ 90 days 17,282 17,267 53 7,770 7,843 24 > 90 days 15,945 16,108 48 6,882 7,079 21 Total $ 89,966 $ 89,806 $ 278 $ 79,182 $ 80,386 $ 247 ________________________________ 1. Includes $161 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2019 and December 31, 2018 , respectively. 2. Excludes $496 million and $437 million of repledged U.S. Treasury securities received as collateral from counterparties as of March 31, 2019 and December 31, 2018 , repsectively. Assets Pledged from Counterparties As of March 31, 2019 and December 31, 2018 , we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions). March 31, 2019 December 31, 2018 Assets Pledged to AGNC 1 Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total U.S. Treasury securities - fair value $ 20,400 $ 10 $ 30 $ 20,440 $ 21,876 $ 35 $ 37 $ 21,948 Cash — 49 — 49 — 129 — 129 Total $ 20,400 $ 59 $ 30 $ 20,489 $ 21,876 $ 164 $ 37 $ 22,077 ________________________________ 1. Includes $496 million and $437 million of repledged U.S. Treasury securities received as collateral from counterparties as of March 31, 2019 and December 31, 2018 , respectively. U.S Treasury securities received as collateral under our reverse repurchase agreements for which we use to cover short sales of U.S. Treasury securities are accounted for as securities borrowing transactions. We recognize a corresponding obligation to return the borrowed securities at fair value on the accompanying consolidated balance sheets based on the value of the underlying borrowed securities as of the reporting date. Cash collateral received is recognized in cash and cash equivalents with a corresponding amount recognized in accounts payable and other accrued liabilities on the accompanying consolidated balance sheets. Offsetting Assets and Liabilities Certain of our repurchase agreements and derivative transactions are governed by underlying agreements that generally provide for a right of setoff under master netting arrangements (or similar agreements), including in the event of default or in the event of bankruptcy of either party to the transactions. We present our assets and liabilities subject to such arrangements on a gross basis in our consolidated balance sheets. The following tables present information about our assets and liabilities that are subject to master netting arrangements and can potentially be offset on our consolidated balance sheets as of March 31, 2019 and December 31, 2018 (in millions): Offsetting of Financial and Derivative Assets Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Assets Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Net Amount Financial Instruments Collateral Received 2 March 31, 2019 Interest rate swap and swaption agreements, at fair value 1 $ 162 $ — $ 162 $ (1 ) $ (59 ) $ 102 TBA securities, at fair value 91 — 91 (21 ) — 70 Receivable under reverse repurchase agreements 20,430 — 20,430 (17,353 ) (3,072 ) 5 Total $ 20,683 $ — $ 20,683 $ (17,375 ) $ (3,131 ) $ 177 December 31, 2018 Interest rate swap and swaption agreements, at fair value 1 $ 163 $ — $ 163 $ — $ (158 ) $ 5 TBA securities, at fair value 110 — 110 (40 ) — 70 Receivable under reverse repurchase agreements 21,813 — 21,813 (17,236 ) (4,575 ) 2 Total $ 22,086 $ — $ 22,086 $ (17,276 ) $ (4,733 ) $ 77 Offsetting of Financial and Derivative Liabilities Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Liabilities Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Net Amount Financial Instruments Collateral Pledged 2 March 31, 2019 Interest rate swap agreements, at fair value 1 $ 1 $ — $ 1 $ (1 ) $ — $ — TBA securities, at fair value 21 — 21 (21 ) — — Repurchase agreements 86,685 — 86,685 (17,353 ) (69,332 ) — Total $ 86,707 $ — $ 86,707 $ (17,375 ) $ (69,332 ) $ — December 31, 2018 Interest rate swap agreements, at fair value 1 $ — $ — $ — $ — $ — $ — TBA securities, at fair value 40 — 40 (40 ) — — Repurchase agreements 75,717 — 75,717 (17,236 ) (58,481 ) — Total $ 75,757 $ — $ 75,757 $ (17,276 ) $ (58,481 ) $ — ________________________________ 1. Reported under derivative assets / liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 6 for a reconciliation of derivative assets / liabilities, at fair value to their sub-components. 2.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We determine the fair value of our financial instruments based on our estimate of the price that would be received to sell the asset or paid to transfer the liability in an orderly transaction between market participants at the measurement date. We typically obtain price estimates from multiple third-party pricing services and dealers or, if applicable, the clearing exchange (see Note 3 for further details.) We utilize a three-level valuation hierarchy for disclosure of fair value measurements. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. A financial instrument's categorization within the hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The three levels of valuation hierarchy are defined as follows: • Level 1 Inputs —Quoted prices (unadjusted) for identical unrestricted assets and liabilities in active markets that are accessible at the measurement date. • Level 2 Inputs —Quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable. • Level 3 Inputs —Instruments with primarily unobservable market data that cannot be corroborated. The availability of observable inputs can vary by instrument and is affected by a wide variety of factors, including the type of instrument, whether the instrument is new and not yet established in the marketplace and other characteristics particular to the instrument. Third-party pricing sources may also use certain unobservable inputs, such as assumptions of future levels of prepayment, defaults and loss severities, especially when estimating fair values for securities with lower levels of recent trading activity. We make inquiries of third-party pricing sources to understand the significant inputs and assumptions they used to determine their prices. We also review third-party price estimates and perform procedures to validate their reasonableness, including an analysis of the range of estimates for each position, comparison to recent trade activity for similar securities, and for consistency with market conditions observed as of the measurement date. While we do not adjust prices we obtain from pricing sources, we will exclude prices for securities from our estimation of fair value if we determine (based on our validation procedures and our market knowledge and expertise) that the price is significantly different from what observable market data would indicate and we cannot obtain an understanding from the third-party source as to the significant inputs used to determine the price. The validation procedures described above also influence our determination of the appropriate fair value measurement categorization. The following table provides a summary of our assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2019 and December 31, 2018 based on their categorization within the valuation hierarchy (in millions). There were no transfers between valuation hierarchy levels during the periods presented. March 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 93,044 $ — $ — $ 82,291 $ — Agency securities transferred to consolidated VIEs — 425 — — 436 — Credit risk transfer securities — 1,129 — — 1,012 — Non-Agency securities — 672 — — 548 — U.S. Treasury securities 121 — — 46 — — Interest rate swaps — 151 — — 126 — Swaptions — 11 — — 37 — TBA securities — 91 — — 110 — Total $ 121 $ 95,523 $ — $ 46 $ 84,560 $ — Liabilities: Debt of consolidated VIEs $ — $ 266 $ — $ — $ 275 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 19,275 — — 21,431 — — Interest rate swaps — 1 — — — — TBA securities — 21 — — 40 — U.S. Treasury futures 31 — — 44 — — Total $ 19,306 $ 288 $ — $ 21,475 $ 315 $ —

Net Income (Loss) Per Common Sh

Net Income (Loss) Per Common Share (Notes)	3 Months Ended
	Mar. 31, 2019
Net Income (Loss) Per Common Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended March 31, 2019 2018 Weighted average number of common shares issued and outstanding 536.3 391.3 Weighted average number of fully vested restricted stock units and performance share units outstanding 0.4 — Weighted average number of common shares outstanding - basic 536.7 391.3 Weighted average number of dilutive unvested restricted stock units and performance share units outstanding 0.5 0.2 Weighted average number of common shares outstanding - diluted 537.2 391.5 Net income available to common stockholders $ 255 $ 415 Net income per common share - basic $ 0.48 $ 1.06 Net income per common share - diluted $ 0.47 $ 1.06
Earnings Per Share [Text Block]	Net Income Per Common Share Basic net income per common share is computed by dividing net income applicable to common stock by the weighted-average number of common shares outstanding and the weighted-average number of vested but not yet issued restricted stock units and performance share units outstanding for the respective period. Diluted earnings per common share includes the impact of dilutive potential common shares outstanding during the period using the treasury stock method. Dilutive potential common shares outstanding include unvested restricted stock units and performance share units granted under our long-term incentive program to employees and non-employee Board of Directors. The following table presents the computations of basic and diluted net income per common share for the periods indicated (shares and dollars in millions): Three Months Ended March 31, 2019 2018 Weighted average number of common shares issued and outstanding 536.3 391.3 Weighted average number of fully vested restricted stock units and performance share units outstanding 0.4 — Weighted average number of common shares outstanding - basic 536.7 391.3 Weighted average number of dilutive unvested restricted stock units and performance share units outstanding 0.5 0.2 Weighted average number of common shares outstanding - diluted 537.2 391.5 Net income available to common stockholders $ 255 $ 415 Net income per common share - basic $ 0.48 $ 1.06 Net income per common share - diluted $ 0.47 $ 1.06

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Preferred Stock We are authorized to designate and issue up to 10.0 million shares of preferred stock in one or more classes or series. As of March 31, 2019 and December 31, 2018 , 8,050 shares were designated as 7.750% Series B Cumulative Redeemable Preferred Stock ("Series B Preferred Stock") and 13,800 shares were designated as 7.00% Series C Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock ("Series C Preferred Stock"). During March 2019, we designated an additional 9,400 shares as 6.875% Series D Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock ("Series D Preferred Stock"). Each share of Series B, C, and D Preferred Stock is represented by 1,000 depositary shares. Our preferred stock ranks senior to our common stock with respect to the payment of dividends and the distribution of assets upon a voluntary or involuntary liquidation, dissolution or winding up of the Company. Our preferred stock has no stated maturity, is not subject to any sinking fund or mandatory redemption and ranks on parity with each other. Under certain circumstances upon a change of control, our preferred stock is convertible to shares of our common stock. Holders of our preferred stock and depository shares underlying our preferred stock have no voting rights, except under limited conditions. Beginning on each series' optional redemption date, such shares will be redeemable at $25.00 per depositary share, plus accumulated and unpaid dividends (whether or not declared), exclusively at our option. The following is a summary of our preferred stock issued and outstanding as of March 31, 2019 (dollars and shares in millions): Preferred Stock Issuance Date Depository Shares Issued and Outstanding Carrying Value Aggregate Liquidation Preference Fixed Rate Optional Redemption Date 2 Fixed-to-Floating Rate Conversion Date Floating Annual Rate Fixed Rate Series B May 8, 2014 7.0 $ 169 $ 175 7.750% May 8, 2019 N/A N/A Fixed-to-Floating Rate 1 Series C August 22, 2017 13.0 315 325 7.000% October 15, 2022 October 15, 2022 3M LIBOR + 5.111% Series D March 6, 2019 9.4 227 235 6.875% April 15, 2024 April 15, 2024 3M LIBOR + 4.332% Total 29.4 $ 711 $ 735 ________________________________ 1. Fixed-to-floating rate redeemable preferred stock accrue dividends at a annual fixed rate of the $25.00 liquidation preference per depository share from the issuance date up to, but not including, the fixed-to-floating rate conversion date; thereafter, dividends will accrue on a floating rate basis equal to 3 month LIBOR plus a fixed spread. 2. Shares may be redeemed prior to our optional redemption date under certain circumstances intended to preserve our qualification as a REIT for U.S federal income tax purposes. At-the-Market Offering Program We are authorized by our Board of Directors to enter into agreements with sales agents to publicly offer and sell shares of our common stock in privately negotiated and/or at-the-market transactions from time-to-time up to a maximum aggregate offering price of our common stock through June 14, 2021. During the quarter ended March 31, 2019 , we did not sell shares of our common stock under the sales agreements. As of March 31, 2019 , shares of our common stock with an aggregate offering price of $660 million remained authorized for issuance under this program. Accumulated Other Comprehensive Income (Loss) The following table summarizes changes to accumulated OCI for the three months ended March 31, 2019 and 2018 (in millions): Three Months Ended March 31, Accumulated Other Comprehensive Income (Loss) 2019 2018 Beginning Balance $ (943 ) $ (345 ) OCI before reclassifications 396 (620 ) (Gain) loss amounts for available-for-sale securities reclassified from accumulated OCI to realized gain (loss) on sale of investment securities 4 (1 ) Ending Balance $ (543 ) $ (966 )

Subsequent Event

Subsequent Event	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Event	Subsequent Events On April 10, 2019 , our Board of Directors declared a monthly dividend of $0.18 per common share payable on May 9, 2019 to common stockholders of record as of April 30, 2019

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policy)	3 Months Ended
	Mar. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Goodwill and Intangible Assets, Policy [Policy Text Block]
Reverse Repurchase Agreements Policy [Policy Text Block]	Reverse Repurchase Agreements and Obligation to Return Securities Borrowed under Reverse Repurchase Agreements We borrow securities to cover short sales of U.S. Treasury securities through reverse repurchase transactions under our master repurchase agreements (see Derivative Instruments
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements We consider the applicability and impact of all Accounting Standards Updates ("ASUs") issued by the Financial Accounting Standards Board. ASUs not listed below were determined to be either not applicable, are not expected to have a significant impact on our consolidated financial statements when adopted or did not have a significant impact on our consolidated financial statements upon adoption. ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. Allowances for credit losses on available-for-sale debt securities will be recognized, rather than direct reductions in the amortized cost of the investments. The new model also requires the estimation of lifetime expected credit losses and corresponding recognition of allowance for losses on trade and other receivables, held-to-maturity debt securities, loans, and other instruments held at amortized cost. The ASU requires certain recurring disclosures and is effective for annual periods, and interim periods within those annual periods, beginning on or after December 15, 2019, with early adoption permitted for annual periods, and interim periods within those annual periods, beginning on or after December 15, 2018. ASU 2016-13 is not expected to have a significant impact on our consolidated financial statements.
Variable Interest Entity Disclosure [Text Block]	.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	.
Investment Securities	Investment Securities Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") guaranteed by the Federal National Mortgage Association ("Fannie Mae"), Federal Home Loan Mortgage Corporation ("Freddie Mac," and together with Fannie Mae, the "GSEs") or the Government National Mortgage Association ("Ginnie Mae"). CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third-party market participants, that transfer a portion of the risk associated with credit losses within pools of conventional residential mortgage loans from the GSEs and/or third parties to private investors. Unlike Agency RMBS, full repayment of the original principal balance of CRT securities is not guaranteed by a GSE or U.S. Government agency; rather, "credit risk transfer" is achieved by writing down the outstanding principal balance of the CRT securities if credit losses on a related pool of loans exceed certain thresholds. By reducing the amount that they are obligated to repay to holders of CRT securities, the GSEs and/or other third parties offset credit losses on the related loans. Non-Agency RMBS and CMBS (together, "Non-Agency MBS") are backed by residential and commercial mortgage loans, respectively, packaged and securitized by a private institution, such as a commercial bank. Non-Agency MBS typically benefit from credit enhancements derived from structural elements, such as subordination, overcollateralization or insurance, but nonetheless carry a higher level of credit exposure than Agency RMBS. All of our securities are reported at fair value on our consolidated balance sheet. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities , requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for securities pursuant to ASC Topic 825, Financial Instruments . Prior to fiscal year 2017, we primarily designated our investment securities as available-for-sale. On January 1, 2017, we began electing the fair value option of accounting for all investment securities acquired after fiscal year 2016. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income ("OCI"). Unrealized gains and losses on securities for which we elected the fair value option or are classified as trading are reported in net income through other gain (loss) during the period in which they occur. Upon the sale of a security designated as available-for-sale, we determine the cost of the security and the amount of unrealized gains or losses to reclassify out of accumulated OCI into earnings based on the specific identification method. In our view, the election of the fair value option simplifies the accounting for investment securities and more appropriately reflects the results of our operations for a reporting period, as the fair value changes for these assets are presented in a manner consistent with the presentation and timing of the fair value changes of our derivative instruments. We estimate the fair value of our investment securities based on prices provided by multiple third-party pricing services and non-binding dealer quotes (collectively "pricing sources"). These pricing sources use various valuation approaches, including market and income approaches, using "Level 2" inputs. The pricing sources primarily utilize a matrix pricing technique that interpolates the estimated fair value of our Agency RMBS based on observed quoted prices for forward contracts in the Agency RMBS "to-be-announced" market ("TBA securities") of the same coupon, maturity and issuer, adjusted to reflect the specific characteristics of the pool of mortgages underlying the Agency security, which may include maximum loan balance, loan vintage, loan-to-value ratio, geography and other characteristics as may be appropriate. The pricing sources may also utilize discounted cash flow model-derived pricing techniques to estimate the fair value of investment securities. Such models incorporate market-based discount rate assumptions based on observable inputs such as recent trading activity, credit data, volatility statistics, benchmark interest rate curves and other market data that are current as of the measurement date and may include certain unobservable inputs, such as assumptions of future levels of prepayment, defaults and loss severities. We review the pricing estimates obtained from the pricing sources and perform procedures to validate their reasonableness. Refer to Note 8 for further discussion of fair value measurements.
Interest Income	Interest Income Interest income is accrued based on the outstanding principal amount of the investment securities and their contractual terms. Premiums or discounts associated with the purchase of Agency RMBS and non-Agency MBS of high credit quality are amortized or accreted into interest income, respectively, over the projected lives of the securities, including contractual payments and estimated prepayments, using the effective interest method in accordance with ASC Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs . We estimate long-term prepayment speeds of our mortgage securities using a third-party service and market data. The third-party service provider estimates prepayment speeds using models that incorporate the forward yield curve, current mortgage rates, mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, interest rate volatility and other factors. We review the prepayment speeds estimated by the third-party service and compare the results to market consensus prepayment speeds, if available. We also consider historical prepayment speeds and current market conditions to validate the reasonableness of the third-party estimates. We review our actual and anticipated prepayment experience on at least a quarterly basis and effective yields are recalculated when differences arise between (i) our previously estimated future prepayments and (ii) actual prepayments to date and our current 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 and Resale Agreements Policy [Policy Text Block]	Repurchase Agreements We finance the acquisition of securities for our investment portfolio primarily through repurchase transactions under master repurchase agreements. Pursuant to ASC Topic 860, Transfers and Servicing
Derivative Instruments	Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate, prepayment, extension and liquidity risks. The objective of our risk management strategy is to reduce fluctuations in net book value over a range of interest rate scenarios. In particular, we attempt to mitigate the risk of the cost of our variable rate liabilities increasing during a period of rising interest rates. The primary instruments that we use are interest rate swaps, options to enter into interest rate swaps ("swaptions"), U.S. Treasury securities and U.S. Treasury futures contracts. We also use forward contracts in the Agency RMBS "to-be-announced" market, or TBA securities, to invest in and finance Agency securities as well as to periodically reduce our exposure to Agency RMBS. We account for derivative instruments in accordance with ASC Topic 815, Derivatives and Hedging ("ASC 815"). ASC 815 requires an entity to recognize all derivatives as either assets or liabilities in our accompanying consolidated balance sheets and to measure those instruments at fair value. None of our derivative instruments have been designated as hedging instruments for accounting purposes under the provisions of ASC 815, consequently changes in the fair value of our derivative instruments are reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with the counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. Derivative instruments in a gain position are reported as derivative assets at fair value and derivative instruments in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Changes in fair value of derivative instruments and periodic settlements related to our derivative instruments are recorded in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized if the counterparties to these instruments fail to perform their obligations under the contracts. Our derivative agreements require that we post or receive collateral to mitigate such risk. We also attempt to minimize our risk of loss by limiting our counterparties to registered central clearing exchanges and major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Interest rate swap agreements We use interest rate swaps to economically hedge the variable cash flows associated with our borrowings made under repurchase agreements. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate based on one or three-month LIBOR ("payer swaps") with terms up to 20 years. The majority of our interest rate swaps are centrally cleared through a registered commodities exchange. We value centrally cleared interest rate swaps using the daily settlement price, or fair value, determined by the clearing exchange based on a pricing model that references observable market inputs, including LIBOR, swap rates and the forward yield curve. Our centrally cleared swaps require that we post an "initial margin" amount determined by the clearing exchange, which is generally intended to be set at a level sufficient to protect the exchange from the interest rate swap's maximum estimated single-day price movement. We also exchange daily settlements of "variation margin" based upon changes in fair value, as measured by the exchange. Pursuant to rules governing central clearing activities, we recognize variation margin settlements as a direct reduction of the carrying value of the interest rate swap asset or liability. We value non-centrally cleared swaps using a combination of third-party valuations obtained from pricing services and the swap counterparty. The third-party valuations are model-driven using observable inputs, including LIBOR, swap rates and the forward yield curve. We also consider both our own and our counterparties' nonperformance risk in estimating the fair value of our interest rate swaps. In considering the effect of nonperformance risk, we assess the impact of netting and credit enhancements, such as collateral postings and guarantees, and have concluded that our own and our counterparty risk is not significant to the overall valuation of these agreements. Interest rate swaptions We purchase interest rate swaptions to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. Interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay and receive interest rates in the future. Our interest rate swaption agreements are not subject to central clearing. The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. We estimate the fair value of interest rate swaptions using a combination of inputs from counterparty and third-party pricing models based on the fair value of the future interest rate swap that we have the option to enter into as well as the remaining length of time that we have to exercise the option, adjusted for non-performance risk, if any. The difference between the premium paid and the fair value of the swaption is reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid. If we sell or exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the cash or the fair value of the underlying interest rate swap and the premium paid. TBA securities A TBA security is a forward contract for the purchase or sale of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS to be delivered into the contract are not known until shortly before the settlement date. We may choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting TBA position, net settling the offsetting positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date (together referred to as a "dollar roll transaction"). The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to equivalent securities settling in the current month. This difference, or "price drop," is the economic equivalent of interest income on the underlying Agency securities, less an implied funding cost, over the forward settlement period (referred to as "dollar roll income"). Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. We account for TBA contracts as derivative instruments since either the TBA contracts do not settle in the shortest period of time possible or we cannot assert that it is probable at inception and throughout the term of the TBA contract that we will physically settle the contract on the settlement date. We account for TBA dollar roll transactions as a series of derivative transactions. We estimate the fair value of TBA securities based on similar methods used to value our Agency RMBS securities. U.S. Treasury securities
Contingencies Disclosure [Text Block]	Loss Contingencies We evaluate the existence of any pending or threatened litigation or other potential claims against the Company in accordance with ASC Topic 450, Contingencies, which requires that we assess the likelihood and range of potential outcomes of any such matters. We are the defendant in three stockholder derivative lawsuits alleging that certain of our current and former directors and officers breached fiduciary duties and wasted corporate assets relating to past renewals of the management agreement with our former external manager and the internalization of our management on July 1, 2016. Although the outcomes of these cases cannot be predicted with certainty, we do not believe that these cases have merit or will result in a material liability, and, as of March 31, 2019

Summary of Significant Accoun_3

Summary of Significant Accounting Policies Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	.
Derivatives, Policy [Policy Text Block]	Derivative Instruments We use a variety of derivative instruments to hedge a portion of our exposure to market risks, including interest rate, prepayment, extension and liquidity risks. The objective of our risk management strategy is to reduce fluctuations in net book value over a range of interest rate scenarios. In particular, we attempt to mitigate the risk of the cost of our variable rate liabilities increasing during a period of rising interest rates. The primary instruments that we use are interest rate swaps, options to enter into interest rate swaps ("swaptions"), U.S. Treasury securities and U.S. Treasury futures contracts. We also use forward contracts in the Agency RMBS "to-be-announced" market, or TBA securities, to invest in and finance Agency securities as well as to periodically reduce our exposure to Agency RMBS. We account for derivative instruments in accordance with ASC Topic 815, Derivatives and Hedging ("ASC 815"). ASC 815 requires an entity to recognize all derivatives as either assets or liabilities in our accompanying consolidated balance sheets and to measure those instruments at fair value. None of our derivative instruments have been designated as hedging instruments for accounting purposes under the provisions of ASC 815, consequently changes in the fair value of our derivative instruments are reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Our derivative agreements generally contain provisions that allow for netting or setting off derivative assets and liabilities with the counterparty; however, we report related assets and liabilities on a gross basis in our consolidated balance sheets. Derivative instruments in a gain position are reported as derivative assets at fair value and derivative instruments in a loss position are reported as derivative liabilities at fair value in our consolidated balance sheets. Changes in fair value of derivative instruments and periodic settlements related to our derivative instruments are recorded in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. Cash receipts and payments related to derivative instruments are classified in our consolidated statements of cash flows according to the underlying nature or purpose of the derivative transaction, generally in the investing section. The use of derivative instruments creates exposure to credit risk relating to potential losses that could be recognized if the counterparties to these instruments fail to perform their obligations under the contracts. Our derivative agreements require that we post or receive collateral to mitigate such risk. We also attempt to minimize our risk of loss by limiting our counterparties to registered central clearing exchanges and major financial institutions with acceptable credit ratings, monitoring positions with individual counterparties and adjusting posted collateral as required. Interest rate swap agreements We use interest rate swaps to economically hedge the variable cash flows associated with our borrowings made under repurchase agreements. Under our interest rate swap agreements, we typically pay a fixed rate and receive a floating rate based on one or three-month LIBOR ("payer swaps") with terms up to 20 years. The majority of our interest rate swaps are centrally cleared through a registered commodities exchange. We value centrally cleared interest rate swaps using the daily settlement price, or fair value, determined by the clearing exchange based on a pricing model that references observable market inputs, including LIBOR, swap rates and the forward yield curve. Our centrally cleared swaps require that we post an "initial margin" amount determined by the clearing exchange, which is generally intended to be set at a level sufficient to protect the exchange from the interest rate swap's maximum estimated single-day price movement. We also exchange daily settlements of "variation margin" based upon changes in fair value, as measured by the exchange. Pursuant to rules governing central clearing activities, we recognize variation margin settlements as a direct reduction of the carrying value of the interest rate swap asset or liability. We value non-centrally cleared swaps using a combination of third-party valuations obtained from pricing services and the swap counterparty. The third-party valuations are model-driven using observable inputs, including LIBOR, swap rates and the forward yield curve. We also consider both our own and our counterparties' nonperformance risk in estimating the fair value of our interest rate swaps. In considering the effect of nonperformance risk, we assess the impact of netting and credit enhancements, such as collateral postings and guarantees, and have concluded that our own and our counterparty risk is not significant to the overall valuation of these agreements. Interest rate swaptions We purchase interest rate swaptions to help mitigate the potential impact of larger, more rapid changes in interest rates on the performance of our investment portfolio. Interest rate swaptions provide us the option to enter into an interest rate swap agreement for a predetermined notional amount, stated term and pay and receive interest rates in the future. Our interest rate swaption agreements are not subject to central clearing. The premium paid for interest rate swaptions is reported as an asset in our consolidated balance sheets. We estimate the fair value of interest rate swaptions using a combination of inputs from counterparty and third-party pricing models based on the fair value of the future interest rate swap that we have the option to enter into as well as the remaining length of time that we have to exercise the option, adjusted for non-performance risk, if any. The difference between the premium paid and the fair value of the swaption is reported in gain (loss) on derivative instruments and other securities, net in our consolidated statements of comprehensive income. If a swaption expires unexercised, the realized loss on the swaption would be equal to the premium paid. If we sell or exercise a swaption, the realized gain or loss on the swaption would be equal to the difference between the cash or the fair value of the underlying interest rate swap and the premium paid. TBA securities A TBA security is a forward contract for the purchase or sale of Agency RMBS at a predetermined price, face amount, issuer, coupon and stated maturity on an agreed-upon future date. The specific Agency RMBS to be delivered into the contract are not known until shortly before the settlement date. We may choose, prior to settlement, to move the settlement of these securities out to a later date by entering into an offsetting TBA position, net settling the offsetting positions for cash, and simultaneously purchasing or selling a similar TBA contract for a later settlement date (together referred to as a "dollar roll transaction"). The Agency securities purchased or sold for a forward settlement date are typically priced at a discount to equivalent securities settling in the current month. This difference, or "price drop," is the economic equivalent of interest income on the underlying Agency securities, less an implied funding cost, over the forward settlement period (referred to as "dollar roll income"). Consequently, forward purchases of Agency securities and dollar roll transactions represent a form of off-balance sheet financing. We account for TBA contracts as derivative instruments since either the TBA contracts do not settle in the shortest period of time possible or we cannot assert that it is probable at inception and throughout the term of the TBA contract that we will physically settle the contract on the settlement date. We account for TBA dollar roll transactions as a series of derivative transactions. We estimate the fair value of TBA securities based on similar methods used to value our Agency RMBS securities. U.S. Treasury securities
Investment, Policy [Policy Text Block]	Investment Securities Agency RMBS consist of residential mortgage pass-through securities and collateralized mortgage obligations ("CMOs") guaranteed by the Federal National Mortgage Association ("Fannie Mae"), Federal Home Loan Mortgage Corporation ("Freddie Mac," and together with Fannie Mae, the "GSEs") or the Government National Mortgage Association ("Ginnie Mae"). CRT securities are risk sharing instruments issued by the GSEs, and similarly structured transactions issued by third-party market participants, that transfer a portion of the risk associated with credit losses within pools of conventional residential mortgage loans from the GSEs and/or third parties to private investors. Unlike Agency RMBS, full repayment of the original principal balance of CRT securities is not guaranteed by a GSE or U.S. Government agency; rather, "credit risk transfer" is achieved by writing down the outstanding principal balance of the CRT securities if credit losses on a related pool of loans exceed certain thresholds. By reducing the amount that they are obligated to repay to holders of CRT securities, the GSEs and/or other third parties offset credit losses on the related loans. Non-Agency RMBS and CMBS (together, "Non-Agency MBS") are backed by residential and commercial mortgage loans, respectively, packaged and securitized by a private institution, such as a commercial bank. Non-Agency MBS typically benefit from credit enhancements derived from structural elements, such as subordination, overcollateralization or insurance, but nonetheless carry a higher level of credit exposure than Agency RMBS. All of our securities are reported at fair value on our consolidated balance sheet. Accounting Standards Codification ("ASC") Topic 320, Investments—Debt and Equity Securities , requires that at the time of purchase, we designate a security as held-to-maturity, available-for-sale or trading, depending on our ability and intent to hold such security to maturity. Alternatively, we may elect the fair value option of accounting for securities pursuant to ASC Topic 825, Financial Instruments . Prior to fiscal year 2017, we primarily designated our investment securities as available-for-sale. On January 1, 2017, we began electing the fair value option of accounting for all investment securities acquired after fiscal year 2016. Unrealized gains and losses on securities classified as available-for-sale are reported in accumulated other comprehensive income ("OCI"). Unrealized gains and losses on securities for which we elected the fair value option or are classified as trading are reported in net income through other gain (loss) during the period in which they occur. Upon the sale of a security designated as available-for-sale, we determine the cost of the security and the amount of unrealized gains or losses to reclassify out of accumulated OCI into earnings based on the specific identification method. In our view, the election of the fair value option simplifies the accounting for investment securities and more appropriately reflects the results of our operations for a reporting period, as the fair value changes for these assets are presented in a manner consistent with the presentation and timing of the fair value changes of our derivative instruments. We estimate the fair value of our investment securities based on prices provided by multiple third-party pricing services and non-binding dealer quotes (collectively "pricing sources"). These pricing sources use various valuation approaches, including market and income approaches, using "Level 2" inputs. The pricing sources primarily utilize a matrix pricing technique that interpolates the estimated fair value of our Agency RMBS based on observed quoted prices for forward contracts in the Agency RMBS "to-be-announced" market ("TBA securities") of the same coupon, maturity and issuer, adjusted to reflect the specific characteristics of the pool of mortgages underlying the Agency security, which may include maximum loan balance, loan vintage, loan-to-value ratio, geography and other characteristics as may be appropriate. The pricing sources may also utilize discounted cash flow model-derived pricing techniques to estimate the fair value of investment securities. Such models incorporate market-based discount rate assumptions based on observable inputs such as recent trading activity, credit data, volatility statistics, benchmark interest rate curves and other market data that are current as of the measurement date and may include certain unobservable inputs, such as assumptions of future levels of prepayment, defaults and loss severities. We review the pricing estimates obtained from the pricing sources and perform procedures to validate their reasonableness. Refer to Note 8 for further discussion of fair value measurements.
Interest Income [Policy Text Block]	Interest Income Interest income is accrued based on the outstanding principal amount of the investment securities and their contractual terms. Premiums or discounts associated with the purchase of Agency RMBS and non-Agency MBS of high credit quality are amortized or accreted into interest income, respectively, over the projected lives of the securities, including contractual payments and estimated prepayments, using the effective interest method in accordance with ASC Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs . We estimate long-term prepayment speeds of our mortgage securities using a third-party service and market data. The third-party service provider estimates prepayment speeds using models that incorporate the forward yield curve, current mortgage rates, mortgage rates of the outstanding loans, age and size of the outstanding loans, loan-to-value ratios, interest rate volatility and other factors. We review the prepayment speeds estimated by the third-party service and compare the results to market consensus prepayment speeds, if available. We also consider historical prepayment speeds and current market conditions to validate the reasonableness of the third-party estimates. We review our actual and anticipated prepayment experience on at least a quarterly basis and effective yields are recalculated when differences arise between (i) our previously estimated future prepayments and (ii) actual prepayments to date and our current 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.

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Securities by Credit Rating [Table Text Block]	As of March 31, 2019 and December 31, 2018 , our investments in CRT and non-Agency securities had the following credit ratings: March 31, 2019 December 31, 2018 CRT and Non-Agency Security Credit Ratings 1 CRT RMBS CMBS CRT RMBS CMBS AAA $ — $ 156 $ 62 $ — $ 160 $ 52 AA — 42 190 — 17 152 A 17 45 33 17 33 15 BBB 54 63 58 25 43 53 BB 412 8 10 492 8 10 B 600 2 — 453 2 — Not Rated 46 3 — 25 3 — Total $ 1,129 $ 319 $ 353 $ 1,012 $ 266 $ 282 ________________________________ 1.
Available-for-sale Securities [Table Text Block]	March 31, 2019 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 16,709 $ 5,493 $ 23 $ 6 $ — $ — $ 22,231 Unamortized discount (11 ) (2 ) — — — — (13 ) Unamortized premium 849 325 — — — — 1,174 Amortized cost 17,547 5,816 23 6 — — 23,392 Gross unrealized gains 19 5 1 — — — 25 Gross unrealized losses (402 ) (166 ) — — — — (568 ) Total available-for-sale securities, at fair value 17,164 5,655 24 6 — — 22,849 Securities remeasured at fair value through earnings: Par value 42,546 25,501 — 317 409 1,087 69,860 Unamortized discount (74 ) (6 ) — (11 ) (70 ) (13 ) (174 ) Unamortized premium 1,138 834 — — 5 35 2,012 Amortized cost 43,610 26,329 — 306 344 1,109 71,698 Gross unrealized gains 620 340 — 7 10 22 999 Gross unrealized losses (172 ) (101 ) — — (1 ) (2 ) (276 ) Total securities remeasured at fair value through earnings 44,058 26,568 — 313 353 1,129 72,421 Total securities, at fair value $ 61,222 $ 32,223 $ 24 $ 319 $ 353 $ 1,129 $ 95,270 Weighted average coupon as of March 31, 2019 3.83 % 3.92 % 3.72 % 3.86 % 4.65 % 5.69 % 3.88 % Weighted average yield as of March 31, 2019 1 3.24 % 3.30 % 2.06 % 4.22 % 4.61 % 4.75 % 3.29 % ________________________________ 1. Incorporates a weighted average future constant prepayment rate assumption of 10.5% based on forward rates as of March 31, 2019 . December 31, 2018 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 17,591 $ 5,673 $ 25 $ 6 $ — $ — $ 23,295 Unamortized discount (10 ) (2 ) — — — — (12 ) Unamortized premium 912 343 — — — — 1,255 Amortized cost 18,493 6,014 25 6 — — 24,538 Gross unrealized gains 4 2 1 — — — 7 Gross unrealized losses (686 ) (264 ) — — — — (950 ) Total available-for-sale securities, at fair value 17,811 5,752 26 6 — — 23,595 Securities remeasured at fair value through earnings: Par value 39,453 18,428 — 268 281 968 59,398 Unamortized discount (78 ) (9 ) — (10 ) (6 ) — (103 ) Unamortized premium 1,055 638 — — 5 38 1,736 Amortized cost 40,430 19,057 — 258 280 1,006 61,031 Gross unrealized gains 223 57 — 2 3 18 303 Gross unrealized losses (386 ) (243 ) — — (1 ) (12 ) (642 ) Total securities remeasured at fair value through earnings 40,267 18,871 — 260 282 1,012 60,692 Total securities, at fair value $ 58,078 $ 24,623 $ 26 $ 266 $ 282 $ 1,012 $ 84,287 Weighted average coupon as of December 31, 2018 3.82 % 3.87 % 3.37 % 3.83 % 4.58 % 5.86 % 3.86 % Weighted average yield as of December 31, 2018 1 3.28 % 3.28 % 2.04 % 4.22 % 4.68 % 5.16 % 3.31 % ________________________________ 1. Incorporates a weighted average future constant prepayment rate assumption of 7.9% based on forward rates as of December 31, 2018 .
Components of Investment Securities	The following tables summarize our investment securities as of March 31, 2019 and December 31, 2018 , excluding TBA securities, (dollars in millions). Details of our TBA securities as of each of the respective dates are included in Note 6 . March 31, 2019 December 31, 2018 Investment Securities Amortized Cost Fair Value Amortized Fair Value Agency RMBS: Fixed rate $ 92,374 $ 92,502 $ 83,047 $ 81,753 Adjustable rate 199 201 212 213 CMO 555 555 588 583 Interest-only and principal-only strips 166 179 172 178 Multifamily 31 32 — — Total Agency RMBS 93,325 93,469 84,019 82,727 Non-Agency RMBS 313 319 264 266 CMBS 343 353 280 282 CRT securities 1,109 1,129 1,006 1,012 Total investment securities $ 95,090 $ 95,270 $ 85,569 $ 84,287 March 31, 2019 Agency RMBS Non-Agency Investment Securities Fannie Mae Freddie Mac Ginnie Mae RMBS CMBS CRT Total Available-for-sale securities: Par value $ 16,709 $ 5,493 $ 23 $ 6 $ — $ — $ 22,231 Unamortized discount (11 ) (2 ) — — — — (13 ) Unamortized premium 849 325 — — — — 1,174 Amortized cost 17,547 5,816 23 6 — — 23,392 Gross unrealized gains 19 5 1 — — — 25 Gross unrealized losses (402 ) (166 ) — — — — (568 ) Total available-for-sale securities, at fair value 17,164 5,655 24 6 — — 22,849 Securities remeasured at fair value through earnings: Par value 42,546 25,501 — 317 409 1,087 69,860 Unamortized discount (74 ) (6 ) — (11 ) (70 ) (13 ) (174 ) Unamortized premium 1,138 834 — — 5 35 2,012 Amortized cost 43,610 26,329 — 306 344 1,109 71,698 Gross unrealized gains 620 340 — 7 10 22 999 Gross unrealized losses (172 ) (101 ) — — (1 ) (2 ) (276 ) Total securities remeasured at fair value through earnings 44,058 26,568 — 313 353 1,129 72,421 Total securities, at fair value $ 61,222 $ 32,223 $ 24 $ 319 $ 353 $ 1,129 $ 95,270 Weighted average coupon as of March 31, 2019 3.83 % 3.92 % 3.72 % 3.86 % 4.65 % 5.69 % 3.88 % Weighted average yield as of March 31, 2019 1 3.24 % 3.30 % 2.06 % 4.22 % 4.61 % 4.75 % 3.29 %
Summary Of Agency Securities Estimated Weighted Average Life Classifications	The following table summarizes our investments as of March 31, 2019 and December 31, 2018 according to their estimated weighted average life classification (dollars in millions): March 31, 2019 December 31, 2018 Estimated Weighted Average Life of Investment Securities Fair Value Amortized Cost Weighted Average Coupon Weighted Average Yield Fair Value Amortized Cost Weighted Average Coupon Weighted Average Yield ≥ 1 year and ≤ 3 years $ 2,452 $ 2,461 3.94% 2.83% $ 1,690 $ 1,716 3.99% 2.64% > 3 years and ≤ 5 years 18,438 18,225 3.85% 3.35% 5,518 5,586 3.35% 2.73% > 5 years and ≤10 years 74,329 74,354 3.89% 3.29% 72,503 73,588 3.92% 3.37% > 10 years 51 50 3.78% 4.12% 4,576 4,679 3.57% 3.30% Total $ 95,270 $ 95,090 3.88% 3.29% $ 84,287 $ 85,569 3.86% 3.31%
Summary of Continuous Unrealized Loss Position of Available for Sale Securities	The following table presents the gross unrealized loss and fair values of securities classified as available-for-sale by length of time that such securities have been in a continuous unrealized loss position as of March 31, 2019 and December 31, 2018 (in millions): Unrealized Loss Position For Less than 12 Months 12 Months or More Total Securities Classified as Available-for-Sale Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss March 31, 2019 $ 108 $ (1 ) $ 20,119 $ (567 ) $ 20,227 $ (568 ) December 31, 2018 $ 4,783 $ (72 ) $ 18,231 $ (878 ) $ 23,014 $ (950 )
Summary of Net Gain from Sale of Agency Securities	The following table is a summary of our net gain (loss) from the sale of investment securities for the three months ended March 31, 2019 and 2018 by investment classification of accounting (in millions): Three Months Ended March 31, 2019 2018 Investment Securities Available-for-Sale Securities 2 Fair Value Option Securities Total Available-for-Sale Securities 2 Fair Value Option Securities Total Investment securities sold, at cost $ (339 ) $ (4,562 ) $ (4,901 ) $ (387 ) $ (1,003 ) $ (1,390 ) Proceeds from investment securities sold 1 335 4,626 4,961 388 1,000 1,388 Net gain (loss) on sale of investment securities $ (4 ) $ 64 $ 60 $ 1 $ (3 ) $ (2 ) Gross gain on sale of investment securities $ — $ 66 $ 66 $ 3 $ 7 $ 10 Gross loss on sale of investment securities (4 ) (2 ) (6 ) (2 ) (10 ) (12 ) Net gain (loss) on sale of investment securities $ (4 ) $ 64 $ 60 $ 1 $ (3 ) $ (2 ) ________________________________ 1. Proceeds include cash received during the period, plus receivable for investment securities sold during the period as of period end. 2. See Note 10 for a summary of changes in accumulated OCI.

Repurchase Agreements and Rev_2

Repurchase Agreements and Reverse Repurchase Agreements (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Repurchase Agreements [Abstract]
Schedule of Borrowings under Repurchase Agreements and Weighted Average Interest Rates	he following table summarizes our borrowings under repurchase agreements by their remaining maturities as of March 31, 2019 and December 31, 2018 (dollars in millions): March 31, 2019 December 31, 2018 Remaining Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Repurchase Agreements Weighted Average Interest Rate Weighted Average Days to Maturity Agency repo: ≤ 1 month $ 44,624 2.94 % 8 $ 48,533 2.88 % 9 > 1 to ≤ 3 months 26,690 2.66 % 65 20,991 2.57 % 56 > 3 to ≤ 6 months 2,181 2.67 % 125 2,218 2.65 % 167 > 6 to ≤ 9 months 2,450 2.68 % 204 200 3.19 % 208 > 9 to ≤ 12 months 7,554 2.75 % 288 950 2.80 % 279 > 12 to ≤ 24 months 1,825 2.97 % 516 2,200 2.91 % 438 > 24 to ≤ 36 months 1,000 2.67 % 1,044 625 3.11 % 776 Total Agency repo 86,324 2.82 % 81 75,717 2.79 % 49 U.S. Treasury repo: > 1 day to ≤ 1 month 361 2.91 % 1 — — % — Total $ 86,685 2.82 % 81 $ 75,717 2.79 % 49

Derivative and Other Hedging _2

Derivative and Other Hedging Instruments (Tables)	3 Months Ended
	Mar. 31, 2019
Derivative [Line Items]
Schedule of Outstanding Derivatives Not Designated as Hedging Instruments	The table below summarizes fair value information about our derivative and other hedging instrument assets/(liabilities) as of March 31, 2019 and December 31, 2018 (in millions): Derivative and Other Hedging Instruments Balance Sheet Location March 31, 2019 December 31, 2018 Interest rate swaps Derivative assets, at fair value $ 151 $ 126 Swaptions Derivative assets, at fair value 11 37 TBA securities Derivative assets, at fair value 91 110 Total derivative assets, at fair value $ 253 $ 273 Interest rate swaps Derivative liabilities, at fair value $ (1 ) $ — TBA securities Derivative liabilities, at fair value (21 ) (40 ) U.S. Treasury futures - short Derivative liabilities, at fair value (31 ) (44 ) Total derivative liabilities, at fair value $ (53 ) $ (84 ) U.S. Treasury securities - long U.S. Treasury securities, at fair value $ 121 $ 46 U.S. Treasury securities - short Obligation to return securities borrowed under reverse repurchase agreements, at fair value (19,275 ) (21,431 ) Total U.S. Treasury securities, net at fair value $ (19,154 ) $ (21,385 )
Schedule of Interest Rate Swaption Agreements Outstanding	Swaptions Option Underlying Payer Swap Current Option Expiration Date Cost Basis Fair Value Average Months to Current Option Expiration Date 1 Notional Amount Average Fixed Pay Rate Average Receive Rate (LIBOR) Average Term (Years) March 31, 2019 ≤ 1 year $ 71 $ 5 4 $ 2,050 2.98% 3M 7.0 > 1 year ≤ 2 years 18 6 15 500 2.78% 3M 10.0 Total $ 89 $ 11 7 $ 2,550 2.94% 3M 7.6 December 31, 2018 ≤ 1 year $ 80 $ 23 4 $ 3,000 2.96% 3M 7.0 > 1 year ≤ 2 years 18 14 18 500 2.78% 3M 10.0 Total $ 98 $ 37 6 $ 3,500 2.93% 3M 7.4 ________________________________ 1. As of March 31, 2019 and December 31, 2018 , ≤ 1 year notional amount includes $700 million of Bermudan swaptions where the options may be exercised on predetermined dates up to their final exercise date, which is six months prior to the underlying swaps' maturity date. U.S. Treasury Securities March 31, 2019 December 31, 2018 Maturity Face Amount (Short) Cost Basis 1 Fair Value Face Amount (Short) Cost Basis 1 Fair Value 5 years $ 120 $ 120 $ 121 $ (703 ) $ (706 ) $ (713 ) 7 years (12,990 ) (12,976 ) (13,285 ) (14,357 ) (14,325 ) (14,410 ) 10 years (5,745 ) (5,810 ) (5,990 ) (6,240 ) (6,224 ) (6,262 ) Total U.S. Treasury securities $ (18,615 ) $ (18,666 ) $ (19,154 ) $ (21,300 ) $ (21,255 ) $ (21,385 )
US government securities	U.S. Treasury Securities March 31, 2019 December 31, 2018 Maturity Face Amount (Short) Cost Basis 1 Fair Value Face Amount (Short) Cost Basis 1 Fair Value 5 years $ 120 $ 120 $ 121 $ (703 ) $ (706 ) $ (713 ) 7 years (12,990 ) (12,976 ) (13,285 ) (14,357 ) (14,325 ) (14,410 ) 10 years (5,745 ) (5,810 ) (5,990 ) (6,240 ) (6,224 ) (6,262 ) Total U.S. Treasury securities $ (18,615 ) $ (18,666 ) $ (19,154 ) $ (21,300 ) $ (21,255 ) $ (21,385 )
US Government Futures Securities [Table Text Block]	U.S. Treasury Futures March 31, 2019 December 31, 2018 Maturity Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 10 years $ (1,650 ) $ (2,019 ) $ (2,050 ) $ (31 ) $ (1,650 ) $ (1,969 ) $ (2,013 ) $ (44 ) ________________________________ 1.
Summary of Long and Short Position of Derivative Instruments	March 31, 2019 December 31, 2018 TBA Securities by Coupon Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 Notional Amount - Long (Short) Cost Basis Fair Value Net Carrying Value 1 15-Year TBA securities: 3.0% $ 327 $ 328 $ 329 $ 1 $ 567 $ 557 $ 566 $ 9 3.5% 1,969 1,996 2,013 17 1,706 1,708 1,726 18 4.0% 1,083 1,108 1,115 7 1,350 1,370 1,381 11 Total 15-Year TBA securities 3,379 3,432 3,457 25 3,623 3,635 3,673 38 30-Year TBA securities: 3.0% 903 886 899 13 1,028 981 1,003 22 3.5% 3,084 3,095 3,125 30 (2,979 ) (2,943 ) (2,977 ) (34 ) 4.0% (3,148 ) (3,222 ) (3,238 ) (16 ) 3,030 3,073 3,089 16 ≥ 4.5% 2,604 2,694 2,712 18 2,450 2,506 2,534 28 Total 30-Year TBA securities, net 3,443 3,453 3,498 45 3,529 3,617 3,649 32 Total TBA securities, net $ 6,822 $ 6,885 $ 6,955 $ 70 $ 7,152 $ 7,252 $ 7,322 $ 70 ________________________________ 1.
Schedule Of Outstanding Not Designated As Hedging Instruments	The following table summarizes changes in our derivative and other hedge portfolio and their effect on our consolidated statements of comprehensive income for the three months ended March 31, 2019 and 2018 (in millions): Derivative and Other Hedging Instruments Beginning Notional Amount Additions Settlement, Termination, Expiration or Exercise Ending Notional Amount Gain/(Loss) on Derivative Instruments and Other Securities, Net 1 Three months ended March 31, 2019: TBA securities, net $ 7,152 18,442 (18,772 ) $ 6,822 $ 83 Interest rate swaps $ 51,625 5,350 (8,800 ) $ 48,175 (596 ) Payer swaptions $ 3,500 — (950 ) $ 2,550 (27 ) U.S. Treasury securities - short position $ (21,345 ) (4,770 ) 7,380 $ (18,735 ) (425 ) U.S. Treasury securities - long position $ 45 405 (330 ) $ 120 — U.S. Treasury futures contracts - short position $ (1,650 ) (1,650 ) 1,650 $ (1,650 ) (31 ) $ (996 ) Three months ended March 31, 2018: TBA securities, net $ 15,474 43,669 (45,507 ) $ 13,636 $ (292 ) Interest rate swaps $ 43,700 3,150 (1,600 ) $ 45,250 663 Payer swaptions $ 6,650 1,100 (1,000 ) $ 6,750 91 U.S. Treasury securities - short position $ (10,699 ) (662 ) 563 $ (10,798 ) 212 U.S. Treasury securities - long position $ — 959 (734 ) $ 225 — U.S. Treasury futures contracts - short position $ (2,910 ) (2,909 ) 3,439 $ (2,380 ) 62 $ 736 ________________________________ 1.
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Schedule Of Interest Rate Swap Agreement By Remaining Maturity	The following tables summarize certain characteristics of our derivative and other hedging instruments outstanding as of March 31, 2019 and December 31, 2018 (dollars in millions): March 31, 2019 December 31, 2018 Interest Rate Swaps Notional 1 Average Rate 2 Average Average Notional 1 Average Rate 2 Average Average ≤ 3 years $ 20,900 1.71% 2.69% 1.2 $ 19,900 1.63% 2.62% 1.3 > 3 to ≤ 5 years 9,425 2.11% 2.69% 3.7 8,425 2.06% 2.61% 4.0 > 5 to ≤ 7 years 6,225 2.38% 2.67% 5.8 7,875 2.66% 2.66% 6.1 > 7 to ≤ 10 years 9,700 2.30% 2.68% 8.6 10,550 2.36% 2.64% 8.8 > 10 years 1,925 2.30% 2.69% 13.2 4,875 2.77% 2.63% 11.6 Total $ 48,175 2.01% 2.69% 4.3 $ 51,625 2.11% 2.63% 5.0

Pledged Assets (Tables)

Pledged Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Pledged Assets [Abstract]
Schedule of Securities and Cash Pledged as Collateral from Counterparties [Table Text Block]	As of March 31, 2019 and December 31, 2018 , we had assets pledged to us from counterparties as collateral under our reverse repurchase and derivative agreements summarized in the tables below (in millions). March 31, 2019 December 31, 2018 Assets Pledged to AGNC 1 Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total Reverse Repurchase Agreements Derivative Agreements Repurchase Agreements Total U.S. Treasury securities - fair value $ 20,400 $ 10 $ 30 $ 20,440 $ 21,876 $ 35 $ 37 $ 21,948 Cash — 49 — 49 — 129 — 129 Total $ 20,400 $ 59 $ 30 $ 20,489 $ 21,876 $ 164 $ 37 $ 22,077
Schedule of Financial Instruments Owned and Pledged as Collateral	The following tables summarize our assets pledged as collateral under our funding, derivative and prime broker agreements by type, including securities pledged related to securities sold but not yet settled, as of March 31, 2019 and December 31, 2018 (in millions): March 31, 2019 Assets Pledged to Counterparties 1 Repurchase Agreements 2 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements 3 Total Agency RMBS - fair value $ 89,779 $ 425 $ 174 $ 118 $ 90,496 CRT - fair value 142 — — — 142 Non-Agency - fair value 45 — — — 45 U.S. Treasury securities - fair value 617 — — — 617 Accrued interest on pledged securities 278 1 1 — 280 Restricted cash and cash equivalents 75 — 442 — 517 Total $ 90,936 $ 426 $ 617 $ 118 $ 92,097 December 31, 2018 Assets Pledged to Counterparties 1 Repurchase Agreements 2 Debt of Consolidated VIEs Derivative Agreements Prime Broker Agreements 3 Total Agency RMBS - fair value $ 78,997 $ 436 $ 174 $ 133 $ 79,740 CRT - fair value 141 — — — 141 Non-Agency - fair value 45 — — — 45 U.S. Treasury securities - fair value 437 — — — 437 Accrued interest on pledged securities 246 1 1 — 248 Restricted cash and cash equivalents 77 — 522 — 599 Total $ 79,943 $ 437 $ 697 $ 133 $ 81,210 ________________________________ 1. Includes repledged assets received as collateral from counterparties. 2. Includes $161 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2019 and December 31, 2018 , respectively. 3.
Schedules Of Securities Pledged As Collateral Under Repurchase Agreement	The following table summarizes our securities pledged as collateral under our repurchase agreements by the remaining maturity of our borrowings, including securities pledged related to sold but not yet settled securities, as of March 31, 2019 and December 31, 2018 (in millions). For the corresponding borrowings associated with the following amounts and the interest rates thereon, refer to Note 5 . March 31, 2019 December 31, 2018 Securities Pledged by Remaining Maturity of Repurchase Agreements 1,2 Fair Value of Pledged Securities Amortized Cost of Pledged Securities Accrued Interest on Pledged Securities Fair Value of Pledged Securities Amortized Cost of Pledged Securities Accrued Interest on Pledged Securities ≤ 30 days $ 45,947 $ 45,673 $ 143 $ 49,944 $ 50,654 $ 156 > 30 and ≤ 60 days 10,792 10,758 34 14,586 14,810 46 > 60 and ≤ 90 days 17,282 17,267 53 7,770 7,843 24 > 90 days 15,945 16,108 48 6,882 7,079 21 Total $ 89,966 $ 89,806 $ 278 $ 79,182 $ 80,386 $ 247 ________________________________ 1. Includes $161 million and $163 million of retained interests in our consolidated VIEs pledged as collateral under repurchase agreements as of March 31, 2019 and December 31, 2018 , respectively. 2. Excludes $496 million
Offsetting Assets and Liabilities	The following tables present information about our assets and liabilities that are subject to master netting arrangements and can potentially be offset on our consolidated balance sheets as of March 31, 2019 and December 31, 2018 (in millions): Offsetting of Financial and Derivative Assets Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Assets Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Net Amount Financial Instruments Collateral Received 2 March 31, 2019 Interest rate swap and swaption agreements, at fair value 1 $ 162 $ — $ 162 $ (1 ) $ (59 ) $ 102 TBA securities, at fair value 91 — 91 (21 ) — 70 Receivable under reverse repurchase agreements 20,430 — 20,430 (17,353 ) (3,072 ) 5 Total $ 20,683 $ — $ 20,683 $ (17,375 ) $ (3,131 ) $ 177 December 31, 2018 Interest rate swap and swaption agreements, at fair value 1 $ 163 $ — $ 163 $ — $ (158 ) $ 5 TBA securities, at fair value 110 — 110 (40 ) — 70 Receivable under reverse repurchase agreements 21,813 — 21,813 (17,236 ) (4,575 ) 2 Total $ 22,086 $ — $ 22,086 $ (17,276 ) $ (4,733 ) $ 77
Offsetting Liabilities	Offsetting of Financial and Derivative Liabilities Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Liabilities Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Net Amount Financial Instruments Collateral Pledged 2 March 31, 2019 Interest rate swap agreements, at fair value 1 $ 1 $ — $ 1 $ (1 ) $ — $ — TBA securities, at fair value 21 — 21 (21 ) — — Repurchase agreements 86,685 — 86,685 (17,353 ) (69,332 ) — Total $ 86,707 $ — $ 86,707 $ (17,375 ) $ (69,332 ) $ — December 31, 2018 Interest rate swap agreements, at fair value 1 $ — $ — $ — $ — $ — $ — TBA securities, at fair value 40 — 40 (40 ) — — Repurchase agreements 75,717 — 75,717 (17,236 ) (58,481 ) — Total $ 75,757 $ — $ 75,757 $ (17,276 ) $ (58,481 ) $ — ________________________________ 1. Reported under derivative assets / liabilities, at fair value in the accompanying consolidated balance sheets. Refer to Note 6 for a reconciliation of derivative assets / liabilities, at fair value to their sub-components. 2.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table provides a summary of our assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2019 and December 31, 2018 based on their categorization within the valuation hierarchy (in millions). There were no transfers between valuation hierarchy levels during the periods presented. March 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Agency securities $ — $ 93,044 $ — $ — $ 82,291 $ — Agency securities transferred to consolidated VIEs — 425 — — 436 — Credit risk transfer securities — 1,129 — — 1,012 — Non-Agency securities — 672 — — 548 — U.S. Treasury securities 121 — — 46 — — Interest rate swaps — 151 — — 126 — Swaptions — 11 — — 37 — TBA securities — 91 — — 110 — Total $ 121 $ 95,523 $ — $ 46 $ 84,560 $ — Liabilities: Debt of consolidated VIEs $ — $ 266 $ — $ — $ 275 $ — Obligation to return U.S. Treasury securities borrowed under reverse repurchase agreements 19,275 — — 21,431 — — Interest rate swaps — 1 — — — — TBA securities — 21 — — 40 — U.S. Treasury futures 31 — — 44 — — Total $ 19,306 $ 288 $ — $ 21,475 $ 315 $ —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Preferred Stock [Table Text Block]	The following is a summary of our preferred stock issued and outstanding as of March 31, 2019 (dollars and shares in millions): Preferred Stock Issuance Date Depository Shares Issued and Outstanding Carrying Value Aggregate Liquidation Preference Fixed Rate Optional Redemption Date 2 Fixed-to-Floating Rate Conversion Date Floating Annual Rate Fixed Rate Series B May 8, 2014 7.0 $ 169 $ 175 7.750% May 8, 2019 N/A N/A Fixed-to-Floating Rate 1 Series C August 22, 2017 13.0 315 325 7.000% October 15, 2022 October 15, 2022 3M LIBOR + 5.111% Series D March 6, 2019 9.4 227 235 6.875% April 15, 2024 April 15, 2024 3M LIBOR + 4.332% Total 29.4 $ 711 $ 735 ________________________________ 1. Fixed-to-floating rate redeemable preferred stock accrue dividends at a annual fixed rate of the $25.00 liquidation preference per depository share from the issuance date up to, but not including, the fixed-to-floating rate conversion date; thereafter, dividends will accrue on a floating rate basis equal to 3 month LIBOR plus a fixed spread. 2.
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes changes to accumulated OCI for the three months ended March 31, 2019 and 2018 (in millions): Three Months Ended March 31, Accumulated Other Comprehensive Income (Loss) 2019 2018 Beginning Balance $ (943 ) $ (345 ) OCI before reclassifications 396 (620 ) (Gain) loss amounts for available-for-sale securities reclassified from accumulated OCI to realized gain (loss) on sale of investment securities 4 (1 ) Ending Balance $ (543 ) $ (966 )

Organization (Details)

Organization (Details)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Required Annual Distribution of Taxable Net Income	90.00%
Intended annual distribution of taxable net income	100.00%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details)	3 Months Ended
	Mar. 31, 2019
Derivative [Line Items]
Document Period End Date	Mar. 31, 2019
Required Annual Distribution of Taxable Net Income	90.00%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Document Period End Date	Mar. 31, 2019
Other Long-term Debt	$ 266	$ 275
Debt Instrument, Description of Variable Rate Basis	LIBOR
Spread Over LIBOR	41	40
Weighted Average Life Other Debt	5 years 10 months 24 days	6 years 1 month 6 days

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Document Period End Date	Mar. 31, 2019
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	$ 95,300	$ 84,300
Weighted average expected constant prepayment rate	10.50%	7.90%
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ (425)	$ (436)
Debt, at fair value	(266)	(275)
Agency Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Unamortized premium balance	3,000	2,900
TBA securities Fifteen Year and Thirty Year Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Net long TBA position, at fair value	7,000	7,300
TBA, net carrying value	$ 70	$ 70
Credit Risk Transfer Securities [Member] | Minimum [Member]
Debt Securities, Available-for-sale [Line Items]
Weighted Average Coupon Rate	3.00%	3.90%
Underlying Collateral Coupon	3.70%	3.80%
Credit Risk Transfer Securities [Member] | Maximum [Member]
Debt Securities, Available-for-sale [Line Items]
Weighted Average Coupon Rate	8.80%	9.50%
Underlying Collateral Coupon	4.90%	4.80%

Investment Securities (Summary

Investment Securities (Summary of Investment in Agency Security) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	$ 95,090	$ 85,569
Document Period End Date	Mar. 31, 2019
Debt Securities, Trading and Available-for-sale	$ 95,270	84,287
Total agency MBS, at fair value	93,469	82,727
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	313	264
Debt Securities, Trading and Available-for-sale	319	266
Commercial Mortgage Backed Securities [Member]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	343	280
Debt Securities, Trading and Available-for-sale	353	282
Credit Risk Transfer Securities [Member]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	1,109	1,006
Debt Securities, Trading and Available-for-sale	1,129	1,012
Fixed Income Securities [Member] | Agency Securities [Member]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	92,374	83,047
Debt Securities, Trading and Available-for-sale	92,502	81,753
Adjustable-Rate [Member] | Agency Securities [Member]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	199	212
Debt Securities, Trading and Available-for-sale	201	213
Collateralized Mortgage Obligations [Member] | Agency Securities [Member]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	555	588
Debt Securities, Trading and Available-for-sale	555	583
Multifamily [Member] | Agency Securities [Member]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	31	0
Debt Securities, Trading and Available-for-sale	32	0
Interest Only And Principal Only Strip [Member] | Agency Securities [Member]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	166	172
Debt Securities, Trading and Available-for-sale	179	178
Agency Securities [Member]
Debt Securities, Trading and Available-for-sale, Amortized Cost Basis	$ 93,325	$ 84,019

Investment Securities (Componen

Investment Securities (Components Of Investment Securities) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Document Period End Date	Mar. 31, 2019
Agency securities transferred to consolidated VIEs	$ 425	$ 436
Debt Securities, Trading	72,421	60,692
Debt Securities, Trading and Available-for-sale	95,270	84,287
Amortized cost	$ 95,090	$ 85,569
Weighted average coupon	3.88%	3.86%
Weighted average yield	3.29%	3.31%
Future Prepayment Rate Assumption Of Investment Portfolio	10.50%	7.90%
Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 22,231	$ 23,295
Unamortized discount	(13)	(12)
Unamortized premium	1,174	1,255
Amortized cost	23,392	24,538
Gross unrealized gains	25	7
Gross unrealized losses	(568)	(950)
Total available-for-sale securities, at fair value	22,849	23,595
Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(174)	(103)
Unamortized premium	2,012	1,736
Debt Securities, Trading, Unrealized Gain	999	303
Debt Securities, Trading, Unrealized Loss	276	642
Trading Securities, Cost	71,698	61,031
Trading Securities Par	69,860	59,398
Fannie Mae [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	44,058	40,267
Debt Securities, Trading and Available-for-sale	$ 61,222	$ 58,078
Weighted average coupon	3.83%	3.82%
Weighted average yield	3.24%	3.28%
Fannie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 16,709	$ 17,591
Unamortized discount	(11)	(10)
Unamortized premium	849	912
Amortized cost	17,547	18,493
Gross unrealized gains	19	4
Gross unrealized losses	(402)	(686)
Total available-for-sale securities, at fair value	17,164	17,811
Fannie Mae [Member] | Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(74)	(78)
Unamortized premium	1,138	1,055
Debt Securities, Trading, Unrealized Gain	620	223
Debt Securities, Trading, Unrealized Loss	172	386
Trading Securities, Cost	43,610	40,430
Trading Securities Par	42,546	39,453
Freddie Mac [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	26,568	18,871
Debt Securities, Trading and Available-for-sale	$ 32,223	$ 24,623
Weighted average coupon	3.92%	3.87%
Weighted average yield	3.30%	3.28%
Freddie Mac [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 5,493	$ 5,673
Unamortized discount	(2)	(2)
Unamortized premium	325	343
Amortized cost	5,816	6,014
Gross unrealized gains	5	2
Gross unrealized losses	(166)	(264)
Total available-for-sale securities, at fair value	5,655	5,752
Freddie Mac [Member] | Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(6)	(9)
Unamortized premium	834	638
Debt Securities, Trading, Unrealized Gain	340	57
Debt Securities, Trading, Unrealized Loss	101	243
Trading Securities, Cost	26,329	19,057
Trading Securities Par	25,501	18,428
Ginnie Mae [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	0	0
Debt Securities, Trading and Available-for-sale	$ 24	$ 26
Weighted average coupon	3.72%	3.37%
Weighted average yield	2.06%	2.04%
Ginnie Mae [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 23	$ 25
Unamortized discount	0	0
Unamortized premium	0	0
Amortized cost	23	25
Gross unrealized gains	1	1
Gross unrealized losses	0	0
Total available-for-sale securities, at fair value	24	26
Ginnie Mae [Member] | Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	0	0
Unamortized premium	0	0
Debt Securities, Trading, Unrealized Gain	0	0
Debt Securities, Trading, Unrealized Loss	0	0
Trading Securities, Cost	0	0
Trading Securities Par	0	0
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	313	260
Debt Securities, Trading and Available-for-sale	$ 319	$ 266
Weighted average coupon	3.86%	3.83%
Weighted average yield	4.22%	4.22%
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 6	$ 6
Unamortized discount	0	0
Unamortized premium	0	0
Amortized cost	6	6
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Total available-for-sale securities, at fair value	6	6
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(11)	(10)
Unamortized premium	0	0
Debt Securities, Trading, Unrealized Gain	7	2
Debt Securities, Trading, Unrealized Loss	0	0
Trading Securities, Cost	306	258
Trading Securities Par	317	268
Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	353	282
Debt Securities, Trading and Available-for-sale	$ 353	$ 282
Weighted average coupon	4.65%	4.58%
Weighted average yield	4.61%	4.68%
Commercial Mortgage Backed Securities [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 0	$ 0
Unamortized discount	0	0
Unamortized premium	0	0
Amortized cost	0	0
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Total available-for-sale securities, at fair value	0	0
Commercial Mortgage Backed Securities [Member] | Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(70)	(6)
Unamortized premium	5	5
Debt Securities, Trading, Unrealized Gain	10	3
Debt Securities, Trading, Unrealized Loss	1	1
Trading Securities, Cost	344	280
Trading Securities Par	409	281
Credit Risk Transfer Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	1,129	1,012
Debt Securities, Trading and Available-for-sale	$ 1,129	$ 1,012
Weighted average coupon	5.69%	5.86%
Weighted average yield	4.75%	5.16%
Credit Risk Transfer Securities [Member] | Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Par value	$ 0	$ 0
Unamortized discount	0	0
Unamortized premium	0	0
Amortized cost	0	0
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Total available-for-sale securities, at fair value	0	0
Credit Risk Transfer Securities [Member] | Trading Securities [Member]
Schedule of Investments [Line Items]
Unamortized discount	(13)	0
Unamortized premium	35	38
Debt Securities, Trading, Unrealized Gain	22	18
Debt Securities, Trading, Unrealized Loss	2	(12)
Trading Securities, Cost	1,109	1,006
Trading Securities Par	1,087	968
Credit Risk Transfer Securities [Member] | Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading and Available-for-sale	$ 1,129	$ 1,012

Investment Securities (Summar_2

Investment Securities (Summary Of Agency Securities Estimated Weighted Average Life Classifications) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Document Period End Date	Mar. 31, 2019
Agency securities classified as available for sale, Fair value	$ 95,270	$ 84,287
Agency securities classified as available for sale, Amortized cost	$ 95,090	$ 85,569
Weighted Average Coupon	3.88%	3.86%
Weighted Average Yield	3.29%	3.31%
Greater Than One Year and Less Than or Equal to Three Years [Member]
Fair Value	$ 2,452	$ 1,690
Amortized Cost	$ 2,461	$ 1,716
Weighted Average Coupon	3.94%	3.99%
Weighted Average Yield	2.83%	2.64%
Greater Than Three Years and Less Than or Equal to Five Years [Member]
Fair Value	$ 18,438	$ 5,518
Amortized Cost	$ 18,225	$ 5,586
Weighted Average Coupon	3.85%	3.35%
Weighted Average Yield	3.35%	2.73%
Greater Than Five Years [Member]
Fair Value	$ 74,329	$ 72,503
Amortized Cost	$ 74,354	$ 73,588
Weighted Average Coupon	3.89%	3.92%
Weighted Average Yield	3.29%	3.37%
Greater Than Ten Years [Member]
Fair Value	$ 51	$ 4,576
Amortized Cost	$ 50	$ 4,679
Weighted Average Coupon	3.78%	3.57%
Weighted Average Yield	4.12%	3.30%

Investment Securities (Summar_3

Investment Securities (Summary Of Changes In Accumulated OCI For Available-For-Sale Security) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Unrealized Gains and (Losses), Net	$ 400	$ (621)
Agency Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning OCI Balance	(943)	(345)
Unrealized Gains and (Losses), Net	396	(620)
Reversal of Unrealized (Gains) and Losses, Net on Realization	4	(1)
Ending OCI Balance	$ (543)	$ (966)

Investment Securities (Summar_4

Investment Securities (Summary Of Continuous Unrealized Loss Positions Of Available-For-Sale Security) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Document Period End Date	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Member]
Unrealized Loss Position For - Estimated Fair Value - Less than 12 Months	$ 108	$ 4,783
Unrealized Loss Position For - Unrealized Loss - Less than 12 Months	(1)	(72)
Unrealized Loss Position For - Estimated Fair Value - 12 Months or More	20,119	18,231
Unrealized Loss Position For - Unrealized Loss - 12 Months or More	(567)	(878)
Unrealized Loss Position For - Estimated Fair Value - Total	20,227	23,014
Unrealized Loss Position For - Unrealized Loss - Total	$ (568)	$ (950)

Investment Securities (Summar_5

Investment Securities (Summary Of Net Gain From Sale Of Agency Securities) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cost of Sale of Fair Value Option Securities	$ (4,562)	$ (1,003)
Cost of Sale of Investment Securities	(4,901)	(1,390)
Proceeds from agency MBS sold	5,103	1,403
Net gain (loss) on sale of investment securities	60	(2)
Available-for-sale Securities [Member]
Agency MBS sold, at cost	(339)	(387)
Proceeds from agency MBS sold	335	388
Net gain (loss) on sale of investment securities		1
Gross gain on sale of investment securities	0	3
Gross loss on sale of investment securities	(4)	(2)
Securities Remeasured at Fair Value [Member]
Proceeds from agency MBS sold	4,626	1,000
Net gain (loss) on sale of investment securities		(3)
Gross gain on sale of investment securities	66	7
Gross loss on sale of investment securities	(2)	(10)
Securities (Assets) [Member]
Proceeds from agency MBS sold	4,961	1,388
Net gain (loss) on sale of investment securities	60	(2)
Gross gain on sale of investment securities	66	10
Gross loss on sale of investment securities	(6)	$ (12)
Cost and Proceeds of Investment Securities [Member] | Available-for-sale Securities [Member]
Net gain (loss) on sale of investment securities	(4)
Cost and Proceeds of Investment Securities [Member] | Securities Remeasured at Fair Value [Member]
Net gain (loss) on sale of investment securities	64
Gross Gain & Loss of Investment Securities [Member] | Available-for-sale Securities [Member]
Net gain (loss) on sale of investment securities	(4)
Gross Gain & Loss of Investment Securities [Member] | Securities Remeasured at Fair Value [Member]
Net gain (loss) on sale of investment securities	$ 64

Investment Securities Securitie

Investment Securities Securities by Credit Rating (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Document Period End Date	Mar. 31, 2019
Debt Securities, Trading	$ 72,421	$ 60,692
Debt Securities, Trading and Available-for-sale	95,270	84,287
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	313	260
Debt Securities, Trading and Available-for-sale	319	266
Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	353	282
Debt Securities, Trading and Available-for-sale	353	282
Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	1,129	1,012
Debt Securities, Trading and Available-for-sale	1,129	1,012
Securities Remeasured at Fair Value [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading and Available-for-sale	1,129	1,012
BBB Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	63	43
BBB Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	58	53
BBB Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	54	25
BB Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	8	8
BB Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	10	10
BB Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	412	492
AAA Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	156	160
AAA Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	62	52
AAA Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
AA Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	42	17
AA Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	190	152
AA Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
A Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	45	33
A Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	33	15
A Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	17	17
B Rating [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	2	2
B Rating [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
B Rating [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	600	453
Not Rated [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	3	3
Not Rated [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	0	0
Not Rated [Member] | Credit Risk Transfer Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Trading	$ 46	$ 25

Repurchase Agreements And Rev_3

Repurchase Agreements And Reverse Repurchase Agreements (Narrative) (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019USD ($)days	Dec. 31, 2018USD ($)days
Assets Sold under Agreements to Repurchase [Line Items]
Document Period End Date	Mar. 31, 2019
Receivable Under Reverse Repurchase Agreements	$ 20,430	$ 21,813
Securities Sold under Agreements to Repurchase	86,685	75,717
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 19,275	$ 21,431
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.82%	2.79%
Debt of consolidated variable interest entities, at fair value	$ (266)	$ (275)
Description of variable rate basis	LIBOR
Basis spread over LIBOR	41	40
Weighted average life of other debt	5 years 10 months 24 days	6 years 1 month 6 days
TBA securities Fifteen Year and Thirty Year Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Fair Value, Net	$ 70	$ 70
TBA and Forward Settling Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Derivative, Forward Settlement Value	6,885	7,252
Derivative, Fair Value, Net	70	70
Forward Contracts [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	$ 10,700	$ 10,700
Weighted Average Forward Start Days | days	85	9
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.55%	2.90%
Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	$ 86,324	$ 75,717
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.82%	2.79%
Bethesda Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Percentage of Repurchase Agreement Funding	41.00%	35.00%
FICC [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Percentage of Repurchase Agreement Funding	40.00%	33.00%
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 5,600	$ 4,500

Repurchase Agreements And Other

Repurchase Agreements And Other Debt (Repurchase Arrangements And Weighted Average Interest Rates Classified By Original Maturities) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)days	Dec. 31, 2018USD ($)days
Document Period End Date	Mar. 31, 2019
Repurchase Agreements	$ 86,685	$ 75,717
Weighted Average Interest Rate	2.82%	2.79%
Weighted Average Days to Maturity | days	81	49
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 19,275	$ 21,431
Maturity Overnight [Member]
Repurchase Agreements	18,700	19,500
30 Days or Less [Member]
Repurchase Agreements	$ 44,624	$ 48,533
Weighted Average Interest Rate	2.94%	2.88%
Weighted Average Days to Maturity | days	8	9
1 to 3 Months
Repurchase Agreements	$ 26,690	$ 20,991
Weighted Average Interest Rate	2.66%	2.57%
Weighted Average Days to Maturity | days	65	56
3 to 6 Months
Repurchase Agreements	$ 2,181	$ 2,218
Weighted Average Interest Rate	2.67%	2.65%
Weighted Average Days to Maturity | days	125	167
6 to 9 Months
Repurchase Agreements	$ 2,450	$ 200
Weighted Average Interest Rate	2.68%	3.19%
Weighted Average Days to Maturity | days	204	208
9 to 12 Months
Repurchase Agreements	$ 7,554	$ 950
Weighted Average Interest Rate	2.75%	2.80%
Weighted Average Days to Maturity | days	288	279
12 to 24 Months
Repurchase Agreements	$ 1,825	$ 2,200
Weighted Average Interest Rate	2.97%	2.91%
Weighted Average Days to Maturity | days	516	438
24 to 36 Months
Repurchase Agreements	$ 1,000	$ 625
Weighted Average Interest Rate	2.67%	3.11%
Weighted Average Days to Maturity | days	1,044	776
US Treasury Securities [Member] | 2 Days to 1 Month [Member]
Repurchase Agreements	$ 361	$ 0
Weighted Average Interest Rate	2.91%	0.00%
Weighted Average Days to Maturity | days	1	0
Agency Securities [Member]
Repurchase Agreements	$ 86,324	$ 75,717
Weighted Average Interest Rate	2.82%	2.79%
Weighted Average Days to Maturity | days	81	49
FICC [Member]
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 5,600	$ 4,500

Derivative and Other Hedging _3

Derivative and Other Hedging Instruments (Narrative) (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019USD ($)month	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)month	Dec. 31, 2017USD ($)
Interest Rate Swaption [Member]
Average Maturity (Years)	7 years 7 months 6 days		7 years 4 months 24 days
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration | month	7		6
Notional Amount	$ 2,550		$ 3,500
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(27)	$ 91
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	0	1,100
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	$ (950)	(1,000)
Derivative, Average Fixed Interest Rate	2.94%		2.93%
Interest Rate Derivatives, at Fair Value, Net	$ 11		$ 37
Options At Cost	89		98
TBA and Forward Settling Agency Securities [Member]
Notional Amount	6,822	13,636	7,152	$ 15,474
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	83	(292)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	18,442	43,669
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		(45,507)
US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(31)	62
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(996)	736
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Notional Amount	2,550
Short [Member] | US Treasury Securities [Member]
Notional Amount	18,735	10,798	21,345	10,699
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(425)	212
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	(4,770)	662
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	7,380	(563)
Long [Member] | US Treasury Securities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0	0
Trading Securities Added During the Period	405	959
Notional Amount Of Trading Securities Settlement Expiration During The Period	(330)	(734)
Debt Securities, Trading, and Equity Securities, FV-NI		$ 225	$ 45	$ 0
Long [Member]
Debt Securities, Trading, and Equity Securities, FV-NI	$ 120

Derivative and Other Hedging _4

Derivative and Other Hedging Instruments (Fair Value Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative asset, fair value	$ 253		$ 273
Derivative liability, fair value	(53)		(84)
Derivative assets, at fair value	253		273
Derivative Liability	(53)		(84)
U.S. Treasury securities	121		46
U.S. Treasury Securities - short	(19,275)		(21,431)
Total - (short)/long, net	(19,154)		(21,385)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(996)	$ 736
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	6,822	13,636	7,152	$ 15,474
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	18,442	43,669
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period		(45,507)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	83	(292)
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	48,175		51,625
Derivative liability, fair value	(1)		0
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	5,350	3,150
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(8,800)	(1,600)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(596)	663
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	151		126
Interest Rate Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	2,550		3,500
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	0	1,100
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(950)	(1,000)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(27)	91
Interest Rate Swaption [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative asset, fair value	11		37
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative liability, fair value	(21)		(40)
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	(18,772)
US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(31)	62
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member] | Future [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative [Line Items]
Derivative Liability	(31)		(44)
TBA and Forward Settling Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Purchases Of TBAs And Forward Settling Agency Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative [Line Items]
Derivative assets, at fair value	91		110
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	48,175
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	2,550
Short [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	18,735	10,798	21,345	10,699
Notional Amount Of Derivatives Not Designated As Hedging Instruments Additions During The Period	(4,770)	662
Notional Amount Of Derivatives Not Designated As Hedging Instruments Settlement Expiration During The Period	7,380	(563)
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(425)	212
Long [Member]
Derivative [Line Items]
Debt Securities, Trading, and Equity Securities, FV-NI	120
Long [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0	0
Debt Securities, Trading, and Equity Securities, FV-NI		225	$ 45	$ 0
Trading Securities Added During the Period	405	959
Notional Amount Of Trading Securities Settlement Expiration During The Period	$ (330)	$ (734)

Derivative and Other Hedging _5

Derivative and Other Hedging Instruments (Summary Of Outstanding Interest Rate Swaps) (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019USD ($)month	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)month
Document Period End Date	Mar. 31, 2019
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (996)	$ 736
Payer Swaption [Member]
Interest Rate Derivative Not Designated As Hedging Instruments Receive Rate	3M		3M
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (27)	91
Notional Amount	$ 2,550		$ 3,500
Average Fixed Pay Rate	2.94%		2.93%
Options At Cost	$ 89		$ 98
Interest Rate Derivatives, at Fair Value, Net	$ 11		$ 37
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration | month	7		6
Average Maturity (Years)	7 years 7 months 6 days		7 years 4 months 24 days
Forward Contracts [Member] | Interest Rate Swap [Member]
Derivative, Notional Amount	$ 4,000		$ 5,700
Weighted Average Forward Start Date	2 months 12 days		6 months
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (596)	$ 663
Notional Amount	$ 48,175		$ 51,625
Average Fixed Pay Rate	2.01%		2.11%
Average Receive Rate	2.69%		2.63%
Average Maturity (Years)	4 years 3 months 18 days		5 years
Less Than or Equal to One Year [Member] | Payer Swaption [Member]
Interest Rate Derivative Not Designated As Hedging Instruments Receive Rate	3M		3M
Less Than or Equal to One Year [Member] | Interest Rate Swaption [Member]
Notional Amount	$ 2,050		$ 3,000
Average Fixed Pay Rate	2.98%		2.96%
Options At Cost	$ 71		$ 80
Interest Rate Derivatives, at Fair Value, Net	$ 5		$ 23
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration | month	4		4
Average Maturity (Years)	7 years		7 years
Greater Than One Year and Less Than or Equal to Two Years [Member] | Payer Swaption [Member]
Interest Rate Derivative Not Designated As Hedging Instruments Receive Rate	3M		3M
Greater Than One Year and Less Than or Equal to Two Years [Member] | Interest Rate Swaption [Member]
Notional Amount	$ 500		$ 500
Average Fixed Pay Rate	2.78%		2.78%
Options At Cost	$ 18		$ 18
Interest Rate Derivatives, at Fair Value, Net	$ 6		$ 14
Cash Flow Hedges Derivative Instruments Not Designated As Hedging Instruments Average Months To Expiration | month	15		18
Average Maturity (Years)	10 years		10 years
Greater Than One Year and Less Than or Equal to Three Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 20,900		$ 19,900
Average Fixed Pay Rate	1.71%		1.63%
Average Receive Rate	2.69%		2.62%
Average Maturity (Years)	1 year 2 months 12 days		1 year 3 months 18 days
Greater Than Three Years and Less Than or Equal to Five Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 9,425		$ 8,425
Average Fixed Pay Rate	2.11%		2.06%
Average Receive Rate	2.69%		2.61%
Average Maturity (Years)	3 years 8 months 12 days		4 years
Greater Than Five Years and Less than or Equal to Seven Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 6,225		$ 7,875
Average Fixed Pay Rate	2.38%		2.66%
Average Receive Rate	2.67%		2.66%
Average Maturity (Years)	5 years 9 months 18 days		6 years 1 month 6 days
Greater Than Seven Years and Less than or Equal to Ten Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 9,700		$ 10,550
Average Fixed Pay Rate	2.30%		2.36%
Average Receive Rate	2.68%		2.64%
Average Maturity (Years)	8 years 7 months 6 days		8 years 9 months 18 days
Greater Than Ten Years [Member] | Interest Rate Swap [Member]
Notional Amount	$ 1,925		$ 4,875
Average Fixed Pay Rate	2.30%		2.77%
Average Receive Rate	2.69%		2.63%
Average Maturity (Years)	13 years 2 months 12 days		11 years 7 months 6 days

Derivative and Other Hedging _6

Derivative and Other Hedging Instruments (Remaining Interest Rate Swap Term) (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019USD ($)month	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)month
Document Period End Date	Mar. 31, 2019
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (996)	$ 736
Interest Rate Swaption [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(27)	91
Cost	89		$ 98
Fair Value	$ 11		$ 37
Average Months to Expiration | month	7		6
Derivative Liability, Notional Amount	$ 2,550		$ 3,500
Average Fixed Pay Rate	2.94%		2.93%
Average Maturity (Years)	7 years 7 months 6 days		7 years 4 months 24 days
Payer Swaption [Member]
Average Receive Rate (LIBOR)	3M		3M
Interest Rate Swap [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (596)	$ 663
Derivative Liability, Notional Amount	$ 48,175		$ 51,625
Average Fixed Pay Rate	2.01%		2.11%
Average Maturity (Years)	4 years 3 months 18 days		5 years
Less Than or Equal to One Year [Member] | Interest Rate Swaption [Member]
Cost	$ 71		$ 80
Fair Value	$ 5		$ 23
Average Months to Expiration | month	4		4
Derivative Liability, Notional Amount	$ 2,050		$ 3,000
Average Fixed Pay Rate	2.98%		2.96%
Average Maturity (Years)	7 years		7 years
Less Than or Equal to One Year [Member] | Payer Swaption [Member]
Average Receive Rate (LIBOR)	3M		3M
Greater Than One Year and Less Than or Equal to Three Years [Member] | Interest Rate Swap [Member]
Derivative Liability, Notional Amount	$ 20,900		$ 19,900
Average Fixed Pay Rate	1.71%		1.63%
Average Maturity (Years)	1 year 2 months 12 days		1 year 3 months 18 days
Bermudan [Member] | Interest Rate Swaption [Member]
Derivative Liability, Notional Amount	$ 700
Interest Rate Swaps Excluding Forward Starting [Member] | Interest Rate Swap [Member]
Average Fixed Pay Rate	1.96%		1.98%

Derivative and Other Hedging _7

Derivative and Other Hedging Instruments (US Treasury Securities) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Document Period End Date	Mar. 31, 2019
U.S. Treasury securities, net	$ (19,154)	$ (21,385)
Weighted Average Yield Percentage	3.29%	3.31%
7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	$ (12,990)	$ (14,357)
At Par Value [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(18,615)	(21,300)
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(6,822)	(7,152)
Derivative, Forward Settlement Value	(6,885)	(7,252)
Derivative Asset, Fair Value, Gross Asset	(6,955)	(7,322)
Derivative, Fair Value, Net	70	70
5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	120	(703)
10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(5,745)	(6,240)
10 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	(31)	(44)
Short [Member] | 10 Year Maturity [Member] | US Treasury Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,650)	(1,650)
Derivative, Forward Settlement Value	(2,019)	(1,969)
Derivative Asset, Fair Value, Gross Asset	(2,050)	(2,013)
Fair Value Hedging [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(19,154)	(21,385)
Fair Value Hedging [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(13,285)	(14,410)
Fair Value Hedging [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	121	(713)
Fair Value Hedging [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(5,990)	(6,262)
At Cost Basis [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(18,666)	(21,255)
At Cost Basis [Member] | 7 Years Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	(12,976)	(14,325)
At Cost Basis [Member] | 5 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	120	(706)
At Cost Basis [Member] | 10 Year Maturity [Member]
Derivative [Line Items]
U.S. Treasury securities, net	$ (5,810)	$ (6,224)
US Treasury Securities [Member]
Derivative [Line Items]
Weighted Average Yield Percentage	2.66%

Derivative and Other Hedging _8

Derivative and Other Hedging Instruments (TBA Securities by Coupon and Issuer) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Document Period End Date	Mar. 31, 2019
TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ (6,822)	$ (7,152)
Cost Basis	(6,885)	(7,252)
Net long TBA position, at fair value	(6,955)	(7,322)
TBA, net carrying value	70	70
30 Year Maturity [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(3,443)	(3,529)
Cost Basis	(3,453)	(3,617)
Net long TBA position, at fair value	(3,498)	(3,649)
TBA, net carrying value	45	32
30 Year Maturity [Member] | 3.0% Coupon [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(903)	(1,028)
Cost Basis	(886)	(981)
Net long TBA position, at fair value	(899)	(1,003)
TBA, net carrying value	13	22
30 Year Maturity [Member] | 3.5% Coupon [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(3,084)
Cost Basis	(3,095)
Net long TBA position, at fair value	(3,125)
TBA, net carrying value	30	(34)
30 Year Maturity [Member] | 4.0% Coupon [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount		(3,030)
Cost Basis		(3,073)
Net long TBA position, at fair value		(3,089)
TBA, net carrying value	(16)	16
30 Year Maturity [Member] | 4.5% Coupon [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(2,604)	(2,450)
Cost Basis	(2,694)	(2,506)
Net long TBA position, at fair value	(2,712)	(2,534)
TBA, net carrying value	18	28
30 Year Maturity [Member] | Short [Member] | 3.5% Coupon [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount		(2,979)
Cost Basis		(2,943)
Net long TBA position, at fair value		(2,977)
30 Year Maturity [Member] | Short [Member] | 4.0% Coupon [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(3,148)
Cost Basis	(3,222)
Net long TBA position, at fair value	(3,238)
15 Year Maturity [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(3,379)	(3,623)
Cost Basis	(3,432)	(3,635)
Net long TBA position, at fair value	(3,457)	(3,673)
TBA, net carrying value	25	38
15 Year Maturity [Member] | 3.0% Coupon [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(327)	(567)
Cost Basis	(328)	(557)
Net long TBA position, at fair value	(329)	(566)
TBA, net carrying value	1	9
15 Year Maturity [Member] | 3.5% Coupon [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,969)	(1,706)
Cost Basis	(1,996)	(1,708)
Net long TBA position, at fair value	(2,013)	(1,726)
TBA, net carrying value	17	18
15 Year Maturity [Member] | 4.0% Coupon [Member] | TBA and Forward Settling Agency Securities [Member]
Derivative [Line Items]
Derivative, Notional Amount	(1,083)	(1,350)
Cost Basis	(1,108)	(1,370)
Net long TBA position, at fair value	(1,115)	(1,381)
TBA, net carrying value	$ 7	$ 11

Derivative and Other Hedging _9

Derivative and Other Hedging Instruments (Effect Of Derivative Instruments Not Designated As Hedges On Comprehensive Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	$ (996)	$ 736
Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(3,500)
Additions	0	(1,100)
Settlement, Expirations or Exercise	950	1,000
Notional Amount	(2,550)
Amount Gain/(Loss) Recognized in Income on Derivatives	(27)	91
TBA and Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(7,152)	(15,474)
Additions	(18,442)	(43,669)
Settlement, Expirations or Exercise		45,507
Notional Amount	(6,822)	(13,636)
Amount Gain/(Loss) Recognized in Income on Derivatives	83	(292)
Derivative, Notional Amount	(6,822)		$ (7,152)
Purchases Of TBAs And Forward Settling Agency Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Settlement, Expirations or Exercise	18,772
Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(51,625)
Additions	(5,350)	(3,150)
Settlement, Expirations or Exercise	8,800	1,600
Notional Amount	(48,175)
Amount Gain/(Loss) Recognized in Income on Derivatives	(596)	663
US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	(31)	62
Not Designated as Hedging Instrument [Member] | Interest Rate Swaption [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(2,550)
Derivative, Notional Amount		(6,750)	(3,500)	$ (6,650)
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(48,175)
Derivative, Notional Amount		(45,250)	(51,625)	(43,700)
Short [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(21,345)	(10,699)
Additions	4,770	(662)
Settlement, Expirations or Exercise	(7,380)	563
Notional Amount	(18,735)	(10,798)
Amount Gain/(Loss) Recognized in Income on Derivatives	(425)	212
Long [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Debt Securities, Trading, and Equity Securities, FV-NI	120
Long [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Amount Gain/(Loss) Recognized in Income on Derivatives	0	0
Debt Securities, Trading, and Equity Securities, FV-NI		225	$ 45	$ 0
Trading Securities Added During the Period	405	959
Notional Amount Of Trading Securities Settlement Expiration During The Period	(330)	(734)
Future [Member] | Short [Member] | US Treasury Securities [Member]
Changes in Derivative and Other Hedge Portfolio [Roll Forward]
Notional Amount	(1,650)	(2,910)
Additions	1,650	(2,909)
Settlement, Expirations or Exercise	(1,650)	3,439
Notional Amount	$ (1,650)	$ (2,380)

Pledged Assets (Narrative) (Det

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

Pledged Assets Repurchase Agree

Pledged Assets Repurchase Agreements with Counterparties Greater than or Equal to 5% of Equity at Risk (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)days	Dec. 31, 2018USD ($)days
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Document Period End Date	Mar. 31, 2019
Securities Sold under Agreements to Repurchase | $	$ 86,685	$ 75,717
Risk Of Repurchase Agreement To Stockholders Equity	4.00%
Weighted Average Days to Maturity | days	81	49
FICC [Member]
Repurchase Agreements with Counterparties Greater than or equal to 5% of Equity at Risk [Line Items]
Risk Of Repurchase Agreement To Stockholders Equity	7.00%

Pledged Assets (Assets Pledged

Pledged Assets (Assets Pledged as Collateral) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	$ 89,966	$ 79,182
Document Period End Date	Mar. 31, 2019
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repurchase Agreements	$ 161	163
Accrued interest on pledged securities	280	248
Restricted cash and cash equivalents	517	599
Total Fair Value of Securities Pledged and Accrued Interest	92,097
Total Fair Value Of Agency Securities Pledged And Accrued Interest		81,210
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	89,779	78,997
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	174	174
Accrued interest on pledged securities		1
Restricted cash and cash equivalents	442	522
Total Fair Value of Securities Pledged and Accrued Interest	617
Total Fair Value Of Agency Securities Pledged And Accrued Interest		697
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Accrued interest on pledged securities	278	246
Total Fair Value of Securities Pledged and Accrued Interest	90,936
Total Fair Value Of Agency Securities Pledged And Accrued Interest		79,943
Variable Interest Entity, Primary Beneficiary [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	425	436
Accrued interest on pledged securities	1	1
Total Fair Value of Securities Pledged and Accrued Interest	426
Total Fair Value Of Agency Securities Pledged And Accrued Interest		437
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	118	133
Accrued interest on pledged securities	0	0
Total Fair Value of Securities Pledged and Accrued Interest	118
Total Fair Value Of Agency Securities Pledged And Accrued Interest		133
Includes Sold But Not Yet Settled Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	90,496	79,740
Credit Risk Transfer Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	142	141
Credit Risk Transfer Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	142	141
Credit Risk Transfer Securities [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	0	0
Non-Agency [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	45	45
Non-Agency [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	45	45
Non-Agency [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	0	0
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	617	437
US Treasury Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	617	437
US Treasury Securities [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	0	0
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Accrued interest on pledged securities	1
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash and cash equivalents	75	77
Under Prime Broker Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash and cash equivalents	0	0
Excluding Cash Received [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted cash and cash equivalents	$ 517	$ 599

Pledged Assets (Securities Pled

Pledged Assets (Securities Pledged as Collateral) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Offsetting Assets and Liabilities [Line Items]
Document Period End Date	Mar. 31, 2019
Retained Interests in Consolidated VIE's Pledged as Collateral Under Repo	$ 161	$ 163
Security Owned and Pledged as Collateral, Fair Value	89,966	79,182
Agency Securities Pledged As Collateral Amortized Cost	89,806	80,386
Agency Securities Pledged As Collateral Accrued Interest	278	247
Maturity Less than 30 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	45,947	49,944
Agency Securities Pledged As Collateral Amortized Cost	45,673	50,654
Agency Securities Pledged As Collateral Accrued Interest	143	156
Maturity 31 To 59 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	10,792	14,586
Agency Securities Pledged As Collateral Amortized Cost	10,758	14,810
Agency Securities Pledged As Collateral Accrued Interest	34	46
Maturity 60 To 90 Days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	17,282	7,770
Agency Securities Pledged As Collateral Amortized Cost	17,267	7,843
Agency Securities Pledged As Collateral Accrued Interest	53	24
Maturity over 90 days [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	15,945	6,882
Agency Securities Pledged As Collateral Amortized Cost	16,108	7,079
Agency Securities Pledged As Collateral Accrued Interest	48	21
Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	89,779	78,997
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	174	174
Credit Risk Transfer Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	142	141
Credit Risk Transfer Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	142	141
Credit Risk Transfer Securities [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	0	0
US Treasury Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	617	437
Securities Received as Collateral, Amount Repledged and Sold	496	437
US Treasury Securities [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	617	437
US Treasury Securities [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	0	0
Non-Agency [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	45	45
Non-Agency [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	45	45
Non-Agency [Member] | Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Security Owned and Pledged as Collateral, Fair Value	$ 0	$ 0

Pledged Assets (Assets Pledge_2

Pledged Assets (Assets Pledged from Counterparties) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Offsetting Assets and Liabilities [Line Items]
Document Period End Date	Mar. 31, 2019
Obligation to Return Securities Borrowed Under Reverse Repurchase Agreements at Fair Value	$ 19,275	$ 21,431
Restricted Cash and Cash Equivalents	517	599
Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	49	129
Restricted Cash and Securities Pledged	20,489	22,077
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	30	37
Securities Sold under Agreements to Repurchase [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	30	37
Derivative [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Securities Pledged	59	164
US Treasury Securities [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	20,440	21,948
Reverse Repurchase Agreements [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	20,400	21,876
Reverse Repurchase Agreements [Member] | US Treasury Securities [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	20,400	21,876
Derivative [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	442	522
Derivative [Member] | US Treasury Securities [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Pledged Financial Instruments, Not Separately Reported, Mortgage-Related Securities Available-for-sale or Held-for-investment	10	35
Derivative [Member] | Assets Pledged to Us [Member]
Offsetting Assets and Liabilities [Line Items]
Restricted Cash and Cash Equivalents	$ 49	$ 129

Pledged Assets (Offsetting Asse

Pledged Assets (Offsetting Assets and Liabilities) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Offsetting Assets and Liabilities [Line Items]
Document Period End Date	Mar. 31, 2019
Collateral Received	$ (3,131)
Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	20,683	$ 22,086
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	20,683	22,086
Financial Instruments	(17,375)	(17,276)
Collateral Received		(4,733)
Net Amount	177	77
Assets [Member] | ERROR in label resolution.
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	162	163
Net Amounts of Assets Presented in the Consolidated Balance Sheets	162	163
Financial Instruments	(1)	0
Collateral Received	(59)	(158)
Net Amount	102	5
Assets [Member] | TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	91	110
Net Amounts of Assets Presented in the Consolidated Balance Sheets	91	110
Financial Instruments	(21)	(40)
Net Amount	70	70
Assets [Member] | Reverse Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Net Amount	5	2
Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	86,707	75,757
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	86,707	75,757
Financial Instruments	(17,375)	(17,276)
Collateral Received	(69,332)	(58,481)
Net Amount	0
Liability [Member] | Repurchase Agreements [Member]
Offsetting Assets and Liabilities [Line Items]
Net Amount	0	0
Liability [Member] | ERROR in label resolution.
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	1	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	1	0
Financial Instruments	(1)	0
Collateral Received	0	0
Net Amount	0	0
Liability [Member] | TBA and Forward Settling Agency Securities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	21	40
Net Amounts of Assets Presented in the Consolidated Balance Sheets	21	40
Financial Instruments	(21)	(40)
Collateral Received	0	0
Net Amount	0	0
Reverse Repurchase Agreements [Member] | Assets [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	20,430	21,813
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	20,430	21,813
Financial Instruments	(17,353)	(17,236)
Collateral Received	(3,072)	(4,575)
Repurchase Agreements [Member] | Liability [Member]
Offsetting Assets and Liabilities [Line Items]
Gross Amounts of Recognized Assets	86,685	75,717
Gross Amount Offset in the Consolidated Balance Sheets	0
Net Amounts of Assets Presented in the Consolidated Balance Sheets	86,685	75,717
Financial Instruments	(17,353)	(17,236)
Collateral Received	$ (69,332)	$ (58,481)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
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	$ 31	$ 44
Interest Rate Swaption [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	11	37
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	151	126
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	0
Purchases Of TBAs And Forward Settling Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | TBA and Forward Settling Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
TBA securities	$ 91	110
Document Period End Date	Mar. 31, 2019
Transfers between hierarchy levels	0
Agency securities	$ 93,044	82,291
Agency securities transferred to consolidated VIEs	425	436
Non-Agency Securities, at Fair Value	672	548
Financial Instruments, Owned, Other, at Fair Value	1,129	1,012
U.S. Treasury securities	121	46
TBA securities	253	273
Derivative Liability	53	84
Debt of consolidated variable interest entities, at fair value	266	275
Obligation to return securities borrowed under reverse repurchase agreements, at fair value	19,275	21,431
Interest rate swaps	253	273
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	121	46
Total liabilities	19,306	21,475
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	95,523	84,560
Total liabilities	288	315
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Sale Of TBA And Forward Settling Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	$ 21	$ 40

Net Income (Loss) Per Common _2

Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average Number of Shares Outstanding	536.3	391.3
Weighted Average Number of Fully Vested Restricted Stock Units and Performance Share Units Outstanding	0.4	0
Weighted Average Number of Shares Outstanding, Basic	536.7	391.3
Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units	$ 0.5	$ 0.2
Weighted Average Number of Shares Outstanding, Diluted	537.2	391.5
Net Income (Loss) Available to Common Stockholders, Basic	$ 255	$ 415
Earnings Per Share, Basic	$ 0.48	$ 1.06
Earnings Per Share, Diluted	$ 0.47	$ 1.06

Stockholders' Equity (Preferred

Stockholders' Equity (Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
	May 31, 2014	Mar. 31, 2019	Dec. 31, 2018	May 05, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock B, Value, Issued		$ 169	$ 169
Preferred Stock B, Liquidation Preference, Value		$ 175	175
Document Period End Date		Mar. 31, 2019
Preferred Stock D, Value, Issued		$ 227	0
Preferred Stock D, Liquidation Preference, Value		235	0
Preferred Stock C, Value, Issued		315	315
Preferred Stock C, Liquidation Preference, Value		325	$ 325
Preferred Stock, Value, Issued		711
Preferred Stock, Liquidation Preference, Value		$ 735
Preferred Stock, Shares Authorized		10,000,000
Series B Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Percent Interest Per Share	0.10%
Preferred Stock, Capital Shares Reserved for Future Issuance		8,050
Preferred Stock, Dividend Rate, Percentage		7.75%
Preferred Stock, Liquidation Preference Per Share				$ 25
Series C Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance		13,800
Preferred Stock, Dividend Rate, Percentage		7.00%
Preferred Stock Dividend Payment Rate Variable Rate Spread		5.111%
Series D Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Capital Shares Reserved for Future Issuance		9,400
Preferred Stock, Dividend Rate, Percentage		6.875%
Preferred Stock Dividend Payment Rate Variable Rate Spread		4.30%
Depositary Share [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued		29,400,000
Depositary Share [Member] | Series B Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued		7,000,000
Depositary Share [Member] | Series C Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued		13,000,000
Depositary Share [Member] | Series D Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, Shares Issued		9,400,000

Stockholders' Equity (Accumulat

Stockholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax	$ 400	$ (621)
Agency Securities [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning OCI Balance	(943)	(345)
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax	396	(620)
Amounts reclassified from accumulated OCI	4	(1)
Ending OCI Balance	$ (543)	$ (966)

Stockholders' Equity (At-the-Ma

Stockholders' Equity (At-the-Market Offering Program) (Details) $ in Millions	Mar. 31, 2019USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares Authorized	$ 660

Subsequent Event (Details)

Subsequent Event (Details) - $ / shares	Apr. 10, 2019	Mar. 31, 2019	Mar. 31, 2018
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared		$ 0.54	$ 0.54
Subsequent Event [Member]
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.18

Uncategorized Items - agnc10q33

Label	Element	Value
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 1,520,000,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 1,363,000,000