Assets and Liabilities Related to Non-consolidated VIEs and Maximum Exposure to Losses (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Variable Interest Entity
Total Assets	$ 123,360	$ 121,894	$ 117,543
Total Liabilities	109,083	108,130
Variable Interest Entity, Not Primary Beneficiary | Fifth Third Community Development Corporation Investments
Variable Interest Entity
Total Assets	1,412	1,442
Total Liabilities	425	394
Maximum Exposure	1,412	1,442
Variable Interest Entity, Not Primary Beneficiary | Private Equity Funds
Variable Interest Entity
Total Assets	195	189
Maximum Exposure	302	310
Variable Interest Entity, Not Primary Beneficiary | Loans Receivable
Variable Interest Entity
Total Assets	1,904	1,622
Maximum Exposure	3,600	2,465
Variable Interest Entity, Not Primary Beneficiary | Automobile Loan Securitizations
Variable Interest Entity
Total Assets	5
Maximum Exposure	5
Variable Interest Entity, Not Primary Beneficiary | Restructured Loans
Variable Interest Entity
Total Assets	1	2
Maximum Exposure	$ 1	$ 2