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	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Earnings per share:
Net income attributable to Bancorp	$ 430	$ 265
Dividends on preferred stock	9	177
Net income (loss) available to common shareholders	421	88
Less: Income allocated to participating securities	(2)
Net income allocated to common shareholders	419	88
Earnings per diluted share:
Net income available to common shareholders	421	88
Series G convertible preferred stock	9
Net income available to common shareholders plus assumed conversions	430	88
Less: Income allocated to participating securities	(2)
Net income allocated to common shareholders plus assumed conversions	$ 428	$ 88
Earnings per share:
Net income allocated to common shareholders	915,225,816	880,829,800
Effect of dilutive securities:
Stock-based awards	6,000,000	7,000,000
Series G convertible preferred stock	36,000,000
Warrant related to Series F preferred stock		7,000,000
Net income allocated to common shareholders plus assumed conversions	957,415,527	894,841,321
Earnings per share:
Net income allocated to common shareholders	$ 0.46	$ 0.10
Effect of dilutive securities:
Series G convertible preferred stock	$ (0.01)
Net income allocated to common shareholders plus assumed conversions	$ 0.45	$ 0.10