CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) (USD $) In Millions, unless otherwise specified	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income
Balance at end of period at Dec. 31, 2011		$ 1,565
Balance at beginning of period at Dec. 31, 2011			0	13,814	2,481	642
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee benefit plans and other				(16)
Net income (loss)	(1,092)				(1,092)
Cash dividends declared on preferred stock					(55)
Other-than-temporary impairment on securities held-to-maturity due to the consolidation of a variable interest entity						0
Other comprehensive income, net of tax	230					230
Balance at beginning of period at Sep. 30, 2012	17,569
Balance at end of period at Sep. 30, 2012	16,004			13,798	1,334	872
Balance at end of period at Dec. 31, 2012	17,836	1,565
Balance at beginning of period at Dec. 31, 2012	16,271		0	14,123	1,363	785
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee benefit plans and other				(12)
Net income (loss)	367				367
Cash dividends declared on preferred stock					(55)
Other-than-temporary impairment on securities held-to-maturity due to the consolidation of a variable interest entity	2					(67)
Other comprehensive income, net of tax	(687)					(687)
Balance at beginning of period at Sep. 30, 2013	17,382
Balance at end of period at Sep. 30, 2013	$ 15,817			$ 14,111	$ 1,675	$ 31