Capital Actions (Detail) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended			3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 5.10% fixed-to-floating rate non-cumulative Series H perpetual preferred stock	Mar. 31, 2013 November 6, 2012 ASR	Dec. 31, 2012 November 6, 2012 ASR	Mar. 31, 2013 December 14, 2012 ASR	Dec. 31, 2012 December 14, 2012 ASR	Mar. 31, 2013 January 28, 2013 ASR	Jun. 30, 2013 May 21, 2013 ASR	Sep. 30, 2012 August 2012 Repurchase Program [Member]	Mar. 31, 2013 March 2013 Repurchase Program [Member]
Capital Actions
Redemption of common shares					7,710,761		6,267,410	6,953,028	25,035,519
Repurchase amount	$ (664)	$ (75)			$ 125		$ 100	$ 125	$ 539
Incremental common shares				657,914		127,760		849,037
Repurchase Shares Authorized							100,000,000			100,000,000	100,000,000
Redemption date					Nov. 09, 2012		Dec. 19, 2012	Jan. 31, 2013
Forward contract redemption date				Feb. 12, 2013		Feb. 27, 2013		Apr. 05, 2013
Depository shares			600,000
Preferred Stock Issuance			24,000
Issuance of preferred shares	593
Amount of preferred stock available for issuance	$ 450
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 5.10% through but excluding June 30, 2023, at which time it converts to a quarterly floating rate dividend of three-month LIBOR plus 3.033%
Preferred Stock, Redemption Terms	Subject to any required regulatory approval, the Bancorp may redeem the Series H preferred shares at its option in whole or in part, at any time on or after June 30, 2023 and following a regulatory capital event at any time prior to June 30, 2023