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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings per share:
Net income attributable to Bancorp	$ 340	$ 421	$ 1,096	$ 1,433
Dividends on preferred stock	12		44	18
Net income (loss) available to common shareholders	328	421	1,052	1,415
Less: Income allocated to participating securities	3	3	8	10
Net income allocated to common shareholders	325	418	1,044	1,405
Earnings per diluted share:
Net income available to common shareholders	328	421	1,052	1,415
Series G convertible preferred stock				18
Net income available to common shareholders plus assumed conversions	328	421	1,052	1,433
Less: Income allocated to participating securities	3	3	8	10
Net income allocated to common shareholders plus assumed conversions	$ 325	$ 418	$ 1,044	$ 1,423
Earnings per share:
Net income allocated to common shareholders	829,000,000	880,000,000	838,000,000	870,000,000
Effect of dilutive securities:
Stock-based awards	9,000,000	8,000,000	10,000,000	7,000,000
Series G convertible preferred stock				24,000,000
Net income allocated to common shareholders plus assumed converstions	838,000,000	888,000,000	848,000,000	901,000,000
Earnings per share:
Net income allocated to common shareholders	$ 0.39	$ 0.47	$ 1.25	$ 1.62
Earnings per diluted share:
Net income allocated to common shareholders plus assumed conversions	$ 0.39	$ 0.47	$ 1.23	$ 1.58