Summary of Average Impaired Loans and Leases and Interest Income by Class (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Average impaired loans	$ 2,793		$ 2,993
Interest Income Recognized	26		24
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner Occupied
Average impaired loans	140	[1]	139
Interest Income Recognized	1		1
Commercial Portfolio Segment | Variable Interest Entity, Primary Beneficiary | Commercial Mortgage Loans, Owner Occupied
Average impaired loans	$ 30

[1] Excludes five restructured nonaccrual loans at March 31, 2013 associated with a consolidated variable interest entity, in which the Bancorp has no continuing credit risk due to the risk being assumed by a third party, with an average recorded investment of $30 and an immaterial amount of interest income recognized.