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, 2014	Mar. 31, 2013
Earnings per share:
Net income attributable to Bancorp	$ 318	$ 422
Dividends on preferred stock	9	9
Net income (loss) available to common shareholders	309	413
Less: Income allocated to participating securities	3	3
Net income allocated to common shareholders	306	410
Earnings per diluted share:
Net income available to common shareholders	309	413
Series G convertible preferred stock		9
Net income available to common shareholders plus assumed conversions	309	422
Less: Income allocated to participating securities	3	3
Net income allocated to common shareholders plus assumed conversions	$ 306	$ 419
Earnings per share:
Net income allocated to common shareholders	846,000,000	871,000,000
Effect of dilutive securities:
Stock-based awards	12,000,000	6,000,000
Series G convertible preferred stock		36,000,000
Net income allocated to common shareholders plus assumed converstions	858,000,000	913,000,000
Earnings per share:
Net income allocated to common shareholders	$ 0.36	$ 0.47
Earnings per diluted share:
Net income allocated to common shareholders plus assumed conversions	$ 0.36	$ 0.46