Capital Actions - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Capital Actions
Issuance of preferred shares	$ 297	$ 593
March 2014 Repurchase Program
Capital Actions
Repurchase Shares Authorized	100,000,000
4.90% fixed-to-floating non-cumulative Series J perpetual preferred stock
Capital Actions
Depositary shares	300,000
Preferred stock, issued	12,000
Issuance of preferred shares	$ 297
Preferred stock, liquidation preference	$ 25,000
Preferred Stock, Dividend Payment Terms	The preferred stock accrues dividends, on a non-cumulative, semi-annual basis, at an annual rate of 4.90% through but excluding September 30, 2019, at which time it converts to a quarterly floating rate dividend of three-month LIBOR plus 3.129%.
Preferred Stock, Redemption Terms	Subject to any required regulatory approval, the Bancorp may redeem the Series J preferred shares at its option, in whole or in part, at any time on or after September 30, 2019, or any time prior following a regulatory capital event