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		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings per share:
Net income attributable to Bancorp	$ 381	$ 340	$ 1,056	$ 1,096
Dividends on preferred stock	15	12	52	44
Net income (loss) available to common shareholders	366	328	1,004	1,052
Less: Income allocated to participating securities	4	3	10	8
Net income allocated to common shareholders	362	325	994	1,044
Earnings per diluted share:
Net income available to common shareholders	366	328	1,004	1,052
Net income available to common shareholders plus assumed conversions	366	328	1,004	1,052
Less: Income allocated to participating securities	4	3	10	8
Net income allocated to common shareholders plus assumed conversions	$ 362	$ 325	$ 994	$ 1,044
Earnings per share:
Net income allocated to common shareholders	795,792,825	829,391,505	803,269,681	837,854,214
Effect of dilutive securities:
Stock-based awards	9,000,000	9,000,000	9,000,000	10,000,000
Net income allocated to common shareholders	805,022,588	838,324,420	812,099,365	848,068,145
Earnings per share:
Earnings per share - basic	$ 0.46	$ 0.39	$ 1.24	$ 1.25
Earnings per diluted share:
Net income allocated to common shareholders plus assumed conversions	$ 0.45	$ 0.39	$ 1.22	$ 1.23