Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012 Retained Earnings	Jun. 30, 2011 Retained Earnings	Jun. 30, 2012 Retained Earnings Series A Preferred Stock	Jun. 30, 2011 Retained Earnings Series A Preferred Stock	Jun. 30, 2011 Retained Earnings Series B Preferred Stock	Jun. 30, 2012 Accumulated Other Comprehensive Income (Loss)	Jun. 30, 2011 Accumulated Other Comprehensive Income (Loss)
Income taxes effect on net unrealized (losses) gains on securities available for sale						$ (31)	$ 61
Income taxes effect on net unrealized (losses) gains on derivative financial instruments						$ 5	$ 4
Cash dividends declared on common shares, per share	$ 0.08	$ 0.04
Cash dividends declared on Preferred Stock, per share/annum			$ 3.875	$ 3.875
Cash dividends accrued on Cumulative Series B Preferred Stock, (% per annum)					5.00%