Consolidated Statements of Changes in Equity (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Income taxes effect on net unrealized (losses) gains on securities available for sale	$ (13)	$ (6)
Income taxes effect on net unrealized gains (losses) on derivative financial instruments	(5)	7
Cash dividends declared on common shares, per share	$ 0.05	$ 0.03
Retained Earnings [Member]
Cash dividends declared on common shares, per share	$ 0.05	$ 0.03
Retained Earnings [Member] | Series A Preferred Stock [Member]
Cash dividends declared on Preferred Stock, per share	$ 1.9375	$ 1.9375
Accumulated Other Comprehensive Income (Loss) [Member]
Income taxes effect on net unrealized (losses) gains on securities available for sale	(13)	(6)
Income taxes effect on net unrealized gains (losses) on derivative financial instruments	$ (5)	$ 7