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		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings per share:
Net income attributable to Bancorp	$ 421	$ 363	$ 1,433	$ 1,178
Dividends on preferred stock		9	18	26
Net income (loss) available to common shareholders	421	354	1,415	1,152
Less: Income allocated to participating securities	3	2	10	7
Net income allocated to common shareholders	418	352	1,405	1,145
Earnings per diluted share:
Net income available to common shareholders	421	354	1,415	1,152
Series G convertible preferred stock		9	18	26
Net income available to common shareholders plus assumed conversions	421	363	1,433	1,178
Less: Income allocated to participating securities	3	2	10	7
Net income allocated to common shareholders plus assumed conversions	$ 418	$ 361	$ 1,423	$ 1,171
Earnings per share:
Net income allocated to common shareholders	880,000,000	904,000,000	870,000,000	911,000,000
Effect of dilutive securities:
Stock-based awards	8,000,000	5,000,000	7,000,000	5,000,000
Series G convertible preferred stock		36,000,000	24,000,000	36,000,000
Net income allocated to common shareholders plus assumed converstions	888,000,000	945,000,000	901,000,000	952,000,000
Earnings per share:
Net income allocated to common shareholders	$ 0.47	$ 0.39	$ 1.62	$ 1.26
Effect of dilutive securities:
Series G convertible preferred stock		$ (0.01)	$ (0.04)	$ (0.03)
Net income allocated to common shareholders plus assumed conversions	$ 0.47	$ 0.38	$ 1.58	$ 1.23