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]
Other				(24)
Net income (loss)	(310)				(310)
Cash dividends declared on preferred stock					(37)
Adjustment to add 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	122					122
Balance at end of period at Jun. 30, 2012
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]
Other				(33)
Net income (loss)	363				363
Cash dividends declared on preferred stock					(36)
Adjustment to add other-than-temporary impairment on securities held-to-maturity due to the consolidation of a variable interest entity						(67)
Other comprehensive income, net of tax	(661)					(661)
Balance at beginning and end of period at Jun. 30, 2013	17,402
Balance at end of period at Jun. 30, 2013	$ 15,837			$ 14,090	$ 1,690	$ 57