Consolidated Statement of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance, value at Dec. 31, 2014	$ 9,428	$ 336	$ 4	$ 10,332	$ (1,674)	$ 430
Balance, Preferred Stock, shares at Dec. 31, 2014		6.9
Balance, Common Stock, shares at Dec. 31, 2014			352.8
Net income (loss)	(373)				(373)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	(14)					(14)
Amounts reclassified from accumulated OCI	79					79
Repurchase of common stock	(124)		$ (1)	(123)
Payments for Repurchase of Common Stock	$ 124
Repurchase of common stock shares	(6.3)		(6.3)
Preferred dividends declared	$ (21)				(21)
Common dividends declared	(659)				(659)
Balance, value at Sep. 30, 2015	8,316	$ 336	$ 3	10,209	(2,727)	495
Balance, Preferred Stock, shares at Sep. 30, 2015		6.9
Balance, Common Stock, shares at Sep. 30, 2015			346.5
Balance, value at Dec. 31, 2015	$ 7,971	$ 336	$ 3	10,048	(2,350)	(66)
Balance, Preferred Stock, shares at Dec. 31, 2015	6.9	6.9
Balance, Common Stock, shares at Dec. 31, 2015	337.5		337.5
Net income (loss)	$ (396)				(396)
Other comprehensive income (loss):
Unrealized Gains and (Losses), Net	1,038					1,038
Amounts reclassified from accumulated OCI	38					38
Repurchase of common stock	(116)		$ 0	(116)
Payments for Repurchase of Common Stock	$ 116
Repurchase of common stock shares	(6.5)		(6.5)
Preferred dividends declared	$ (21)				(21)
Common dividends declared	(583)				(583)
Balance, value at Sep. 30, 2016	$ 7,931	$ 336	$ 3	$ 9,932	$ (3,350)	$ 1,010
Balance, Preferred Stock, shares at Sep. 30, 2016	6.9	6.9
Balance, Common Stock, shares at Sep. 30, 2016	331.0		331.0