Assets and Liabilities Related to Non-consolidated VIEs and Maximum Exposure to Losses (Detail) - Variable Interest Entity, Not Primary Beneficiary - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Fifth Third Community Development Corporation Investments
Variable Interest Entity [Line Items]
Total Assets	$ 1,447	$ 1,432
Total Liabilities	368	364
Maximum Exposure	1,447	1,432
Private Equity Funds
Variable Interest Entity [Line Items]
Total Assets	211	189
Maximum Exposure	271	267
Loans Receivable
Variable Interest Entity [Line Items]
Total Assets	1,916	1,900
Maximum Exposure	2,991	2,759
Automobile Loan [Member]
Variable Interest Entity [Line Items]
Total Assets	1	2
Maximum Exposure	$ 1	$ 2