Consolidated Statement Of Changes In Equity (USD $) In Millions	Total	Common stock and paid-in capital [Member]	Preferred stock [Member]	Retained earnings (accumulated deficit) [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2013	$ 14,208	$ 20,939	$ 1,255	$ (7,710)	$ (276)	$ 0
Net income (loss)	227			227
Preferred stock dividends	(68)			(68)
Other comprehensive income (loss)	92				92
Ending Balance at Mar. 31, 2014	14,459	20,939	1,255	(7,551)	(184)	0
Beginning Balance at Dec. 31, 2014	15,399	21,038	1,255	(6,828)	(66)	0
Net income (loss)	576			576
Preferred stock dividends	(67)			(67)
Employee Benefits and Share-based Compensation	10	10
Other comprehensive income (loss)	31				31
Share repurchases related to employee stock-based compensation awards	(15)					(15)
Ending Balance at Mar. 31, 2015	$ 15,934	$ 21,048	$ 1,255	$ (6,319)	$ (35)	$ (15)