Consolidated Statements of Changes in Stockholder's Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Balance, beginning (Previously Reported) at Dec. 31, 2014	$ 230
Balance, beginning at Dec. 31, 2014	15,168	$ 136	$ 7,232	$ 8,265	$ (729)	$ 264
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	307			318		(11)
Other comprehensive income (loss), net of tax	63				63
Compensation-restricted stock units	(25)		(24)	(1)
Other	(13)			0		(13)
Net change	332		(24)	317	63	(24)
Balance, ending at Jun. 30, 2015	15,500	136	7,208	8,582	(666)	240
Balance, beginning (Previously Reported) at Dec. 31, 2015	181
Balance, beginning at Dec. 31, 2015	15,676	136	7,241	8,836	(752)	215
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	331			354		(23)
Other comprehensive income (loss), net of tax	366				366
Compensation-restricted stock units	(2)		(1)	(1)
Other	7			0		7
Net change	702		(1)	353	366	(16)
Balance, ending at Jun. 30, 2016	$ 16,378	$ 136	$ 7,240	$ 9,189	$ (386)	$ 199