Calculation of Earnings Per Share and the Reconciliation of Earnings Per Share to Earnings Per Diluted Share (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Earnings per share:
Net income attributable to Bancorp	$ 1,576	$ 1,297	$ 753
Dividends on preferred stock	35	203	250
Net income (loss) available to common shareholders	1,541	1,094	503
Less: Income allocated to participating securities	(10)	(6)	(3)
Net income allocated to common shareholders	1,531	1,088	500
Earnings per diluted share:
Net income available to common shareholders	1,541	1,094	503
Series G convertible preferred stock	35	35
Net income available to common shareholders plus assumed conversions	1,576	1,129	503
Less: Income allocated to participating securities	(10)	(6)	(3)
Net income allocated to common shareholders plus assumed conversions	$ 1,566	$ 1,123	$ 500
Earnings per share:
Net income allocated to common shareholders	904	906	791
Effect of dilutive securities:
Stock-based awards	6	6	5
Series G convertible preferred stock	36	36
Warrant related to Series F preferred stock		2	3
Net income allocated to common shareholders plus assumed converstions	946	950	799
Earnings per share:
Net income allocated to common shareholders	$ 1.69	$ 1.20	$ 0.63
Effect of dilutive securities:
Series G convertible preferred stock	$ (0.03)	$ (0.02)
Net income allocated to common shareholders plus assumed conversions	$ 1.66	$ 1.18	$ 0.63