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, 2015	Mar. 31, 2014
Earnings per share:
Net income attributable to Bancorp	$ 361	$ 318
Dividends on preferred stock	15	9
Net income (loss) available to common shareholders	346	309
Less: Income allocated to participating securities	3	3
Net income allocated to common shareholders	343	306
Earnings per diluted share:
Net income available to common shareholders	346	309
Net income available to common shareholders plus assumed conversions	346	309
Less: Income allocated to participating securities	3	3
Net income allocated to common shareholders plus assumed conversions	$ 343	$ 306
Earnings per share:
Net income allocated to common shareholders	810,000,000	846,000,000
Effect of dilutive securities:
Stock-based awards	9,000,000	12,000,000
Net income allocated to common shareholders plus assumed converstions	819,000,000	858,000,000
Earnings per share:
Earnings per share - basic	$ 0.42	$ 0.36
Earnings per diluted share:
Net income allocated to common shareholders plus assumed conversions	$ 0.42	$ 0.36