Calculation of Earnings Per Share and the Reconciliation of Earnings Per Share to Earnings Per Diluted Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings per share:
Net income attributable to Bancorp	$ 327	$ 361
Dividends on preferred stock	15	15
Net income (loss) available to common shareholders	312	346
Less: Income allocated to participating securities	3	3
Earnings per share - basic	309	343
Earnings per diluted share:
Net income available to common shareholders	312	346
Net income available to common shareholders plus assumed conversions	312	346
Less: Income allocated to participating securities	3	3
Net income allocated to common shareholders	$ 309	$ 343
Earnings per share:
Net income allocated to common shareholders	773,564,178	810,209,585
Effect of dilutive securities:
Stock-based awards	4,000,000	9,000,000
Net income allocated to common shareholders	778,392,453	818,672,259
Earnings per share:
Earnings per share - basic	$ 0.40	$ 0.42
Earnings per diluted share:
Earnings per share - diluted	$ 0.40	$ 0.42