Variable Interest Entities - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended					3 Months Ended			3 Months Ended		6 Months Ended
	Mar. 31, 2013	Jun. 30, 2014 Variable Interest Entity, Primary Beneficiary Automobile Loan	Jun. 30, 2014 Variable Interest Entity, Primary Beneficiary Fifth Third Community Development Corporation Investments	Dec. 31, 2013 Variable Interest Entity, Primary Beneficiary Fifth Third Community Development Corporation Investments	Jun. 30, 2014 Variable Interest Entity, Not Primary Beneficiary Loans Receivable	Dec. 31, 2013 Variable Interest Entity, Not Primary Beneficiary Loans Receivable	Mar. 31, 2013 Variable Interest Entity, Not Primary Beneficiary Automobile Loan	Jun. 30, 2014 Variable Interest Entity, Not Primary Beneficiary Fifth Third Community Development Corporation Investments	Dec. 31, 2013 Variable Interest Entity, Not Primary Beneficiary Fifth Third Community Development Corporation Investments	Jun. 30, 2014 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Jun. 30, 2013 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Jun. 30, 2014 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Jun. 30, 2013 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Dec. 31, 2013 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Dec. 31, 2013 Variable Interest Entity, Not Primary Beneficiary Restructured Loans
Variable Interest Entity
Carry Value Of Loans Leases Or Lines Of Credit Securitized	$ 509	$ 4,000					$ 509
Maximum Exposure			22	21				1,417	1,436	299		299		294	1
Unfunded commitment amounts					1,100	962				91		91		90
Capital Contribution To Private Equity Funds										$ 5	$ 11	$ 12	$ 14