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		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings per share:
Net income attributable to Bancorp	$ 315	$ 439	$ 676	$ 756
Dividends on preferred stock	23	23	38	32
Net income (loss) available to common shareholders	292	416	638	724
Less: Income allocated to participating securities	3	4	6	6
Net income allocated to common shareholders	289	412	632	718
Earnings per diluted share:
Net income available to common shareholders	292	416	638	724
Net income available to common shareholders plus assumed conversions	292	416	638	724
Less: Income allocated to participating securities	3	4	6	6
Net income allocated to common shareholders plus assumed conversions	$ 289	$ 412	$ 632	$ 718
Earnings per share:
Net income allocated to common shareholders	804,000,000	838,000,000	807,000,000	842,000,000
Effect of dilutive securities:
Stock-based awards	9,000,000	10,000,000	9,000,000	11,000,000
Net income allocated to common shareholders plus assumed converstions	813,000,000	848,000,000	816,000,000	853,000,000
Earnings per share:
Earnings per share - basic	$ 0.36	$ 0.49	$ 0.78	$ 0.85
Earnings per diluted share:
Net income allocated to common shareholders plus assumed conversions	$ 0.36	$ 0.49	$ 0.77	$ 0.84