Consolidated Statements Of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities:
Net income (loss)	$ (396)	$ (373)
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of premiums and discounts on mortgage-backed securities, net	394	330
Amortization of accumulated other comprehensive loss on interest rate swaps de-designated as qualifying hedges	38	79
Amortization of intangible assets	1	0
Stock based compensation	1	0
(Gain) loss on sale of mortgage-backed securities, net	(114)	25
Loss on derivative instruments and other securities, net	1,058	1,090
(Increase) decrease in other assets	37	(73)
Increase (decrease) in accounts payable and other accrued liabilities	10	(8)
Net cash provided by operating activities	1,029	1,070
Investing activities:
Purchases of mortgage-backed securities	(17,275)	(23,792)
Proceeds from sale of mortgage-backed securities	17,032	22,615
Principal collections on mortgage-backed securities	5,997	6,177
Purchases of credit risk transfer securities	(36)	0
Purchases of U.S. Treasury securities	(2,178)	(46,774)
Proceeds from sale of U.S. Treasury securities	5,741	44,237
Net proceeds from (payments on) reverse repurchase agreements	(3,728)	3,755
Net payments on other derivative instruments	(892)	(85)
Purchases of REIT equity securities	0	(11)
Proceeds from sale of REIT equity securities	39	35
Purchase of AGNC Mortgage Management, LLC, net of cash acquired	(555)	0
(Increase) decrease in restricted cash and cash equivalents	577	(700)
Other investing cash flows, net	0	(28)
Net cash provided by investing activities	4,722	5,429
Financing activities:
Proceeds from repurchase arrangements	196,015	317,718
Payments on repurchase agreements	(200,078)	(327,000)
Proceeds from Federal Home Loan Bank advances	2,098	5,437
Payments on Federal Home Loan Bank advances	(2,814)	(1,935)
Payments on debt of consolidated variable interest entities	(100)	(121)
Payments for common stock repurchases	(116)	(124)
Cash dividends paid	(612)	(689)
Net cash used in financing activities	(5,607)	(6,714)
Net change in cash and cash equivalents	144	(215)
Cash and cash equivalents at beginning of period	1,110	1,720
Cash and cash equivalents at end of period	$ 1,254	$ 1,505