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		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Earnings per share:
Net income attributable to Bancorp	$ 385	$ 337	$ 815	$ 602
Dividends on preferred stock	9	9	18	185
Net income (loss) available to common shareholders	376	328	797	417
Less: Income allocated to participating securities	(3)	(2)	(5)	(2)
Net income allocated to common shareholders	373	326	792	415
Earnings per diluted share:
Net income available to common shareholders	376	328	797	417
Series G convertible preferred stock	9	9	18
Net income available to common shareholders plus assumed conversions	385	337	815	417
Less: Income allocated to participating securities	(3)	(2)	(5)	(3)
Net income allocated to common shareholders plus assumed conversions	$ 382	$ 335	$ 810	$ 414
Earnings per share:
Net income allocated to common shareholders	914	915	914	898
Effect of dilutive securities:
Stock-based awards	5	4	6	6
Series G convertible preferred stock	36	36	36
Warrant related to Series F preferred stock				4
Net income allocated to common shareholders plus assumed converstions	955	955	956	908
Earnings per share:
Net income allocated to common shareholders	$ 0.41	$ 0.36	$ 0.87	$ 0.46
Effect of dilutive securities:
Series G convertible preferred stock	$ (0.01)	$ (0.01)	$ (0.02)
Net income allocated to common shareholders plus assumed conversions	$ 0.40	$ 0.35	$ 0.85	$ 0.46