Consolidated Statements Of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest income:
Interest income	$ 315	$ 295	$ 928	$ 1,092
Interest expense	96	77	296	244
Net interest income	219	218	632	848
Other income, net:
Gain (loss) on sale of agency securities, net	61	(39)	114	(25)
Gain (loss) on derivative instruments and other securities, net	242	(778)	(1,058)	(1,090)
Management fee income	4	0	4	0
Total other income, net	307	(817)	(940)	(1,115)
Expenses:
Management fees	0	29	52	88
Compensation and benefits	9	0	9	0
General and administrative expenses	6	5	27	18
Total expenses	15	34	88	106
Net Income (Loss) Attributable to Parent	511	(633)	(396)	(373)
Dividend on preferred stock	7	7	21	21
Net income (loss) available (attributable) to common stockholders	504	(640)	(417)	(394)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	97	(467)	(1,038)	14
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, De-Designated Interest Rate Swaps			(38)	(79)
Unrealized gain on derivative instruments, net	7	24	38	79
Other comprehensive income (loss)	(90)	491	1,076	65
Comprehensive income (loss)	421	(142)	680	(308)
Comprehensive income (loss) available (attributable) to common stockholders	$ 414	$ (149)	$ 659	$ (329)
Weighted average number of common shares outstanding-basic and diluted (shares)	331.0	347.8	332.1	350.9
Net income (loss) per common share - basic and diluted	$ 1.52	$ (1.84)	$ (1.26)	$ (1.12)
Dividends declared per common share	$ 0.56	$ 0.60	$ 1.76	$ 1.88