Assets and Liabilities Related to Non-consolidated VIEs and Maximum Exposure to Losses (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Variable Interest Entity
Total Assets	$ 125,673	$ 121,894	$ 117,483
Total Liabilities	110,993	108,130
Variable Interest Entity, Not Primary Beneficiary | Fifth Third Community Development Corporation Investments
Variable Interest Entity
Total Assets	1,420	1,442
Total Liabilities	421	394
Maximum Exposure	1,420	1,442
Variable Interest Entity, Not Primary Beneficiary | Private Equity Funds
Variable Interest Entity
Total Assets	207	189
Maximum Exposure	303	310
Variable Interest Entity, Not Primary Beneficiary | Loans Receivable
Variable Interest Entity
Total Assets	1,837	1,622
Maximum Exposure	3,783	2,465
Variable Interest Entity, Not Primary Beneficiary | Automobile Loan Securitizations
Variable Interest Entity
Total Assets	4
Maximum Exposure	4
Variable Interest Entity, Not Primary Beneficiary | Restructured Loans
Variable Interest Entity
Total Assets	1	2
Maximum Exposure	$ 1	$ 2