CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) (USD $) In Millions, unless otherwise specified	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated deficit	Accumulated other comprehensive loss
Balance at beginning of period at Dec. 31, 2011		$ 1,575		$ 23,966	$ (18,219)	$ (396)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Series C preferred stock		0
Employee benefit plans, including transfers and other				8
Net income (loss)	(155)				(155)
Dividends on preferred stock					(32)
Other comprehensive income	51					51
Total common shareholder's equity at end of period	5,223
Total shareholders' equity at end of period at Mar. 31, 2012	6,798	1,575	0	23,974	(18,406)	(345)
Balance at beginning of period at Dec. 31, 2012	6,105	1,575		23,974	(19,187)	(257)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Series C preferred stock		0
Employee benefit plans, including transfers and other				(4)
Net income (loss)	226				226
Dividends on preferred stock					(32)
Other comprehensive income	32					32
Total common shareholder's equity at end of period	4,752
Total shareholders' equity at end of period at Mar. 31, 2013	$ 6,327	$ 1,575	$ 0	$ 23,970	$ (18,993)	$ (225)