CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Millions, except Share data, unless otherwise specified	Total	Preferred Stock	Amount	Additional Paid-in Capital	Treasury Stock, at Cost	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2011	$ 23,393	$ 0	$ 6	$ 18,562	$ 0	$ 5,353	$ (528)
Beginning balance (in shares) at Dec. 31, 2011			560,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividend to parent	(150)					(150)
Capital contribution	27			27
Employee stock purchase plan shares purchased	0
Net income (loss)	643					643
Other comprehensive income (loss)	216						216
Total comprehensive income (loss)	859					643	216
Ending balance at Dec. 31, 2012	24,129	0	6	18,589	0	5,846	(312)
Ending balance (in shares) at Dec. 31, 2012			560,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividend to parent	(185)					(185)
Dividends to parent — exchange transactions	(1,000)					(1,000)
Capital contribution	14			14
Employee stock purchase plan shares purchased	0
Net income (loss)	(3,426)					(3,426)
Other comprehensive income (loss)	(336)						(336)
Total comprehensive income (loss)	(3,762)					(3,426)	(336)
Ending balance at Dec. 31, 2013	19,196	0	6	18,603	0	1,235	(648)
Beginning balance (in shares) at Dec. 31, 2013			560,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividend to common stockholders	(16)					(16)
Dividend to parent	(124)					(124)
Dividends to parent — exchange transactions	(666)					(666)
Share-based compensation plans	69			71	(2)
Employee stock purchase plan shares purchased	2			2
Common shares repurchased from parent (in shares)			(14,000,000)
Common shares repurchased from parent	(334)				(334)
Net income (loss)	865					865
Other comprehensive income (loss)	276						276
Total comprehensive income (loss)	1,141					865	276
Ending balance at Dec. 31, 2014	$ 19,268	$ 0	$ 6	$ 18,676	$ (336)	$ 1,294	$ (372)
Ending balance (in shares) at Dec. 31, 2014			546,000,000