Assets and Liabilities Related to Non-consolidated VIEs and Maximum Exposure to Losses (Detail) (Variable Interest Entity, Not Primary Beneficiary, USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fifth Third Community Development Corporation Investments
Variable Interest Entity [Line Items]
Total Assets	$ 1,402	$ 1,432
Total Liabilities	341	364
Maximum Exposure	1,402	1,432
Private Equity Funds
Variable Interest Entity [Line Items]
Total Assets	194	189
Maximum Exposure	262	267
Loans Receivable
Variable Interest Entity [Line Items]
Total Assets	1,979	1,900
Maximum Exposure	2,936	2,759
Automobile Loan Securitizations
Variable Interest Entity [Line Items]
Total Assets	1	2
Maximum Exposure	$ 1	$ 2