Assets and Liabilities Related to Non-consolidated VIEs and Maximum Exposure to Losses (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Variable Interest Entity [Line Items]
Total Assets	$ 121,894	$ 116,967	$ 111,007
Total Liabilities	108,130	103,716
Variable Interest Entity, Not Primary Beneficiary | Fifth Third Community Development Corporation Investments [Member]
Variable Interest Entity [Line Items]
Total Assets	1,442	1,243
Total Liabilities	394	269
Maximum Exposure	1,442	1,243
Variable Interest Entity, Not Primary Beneficiary | Private Equity Funds
Variable Interest Entity [Line Items]
Total Assets	189	161
Total Liabilities		3
Maximum Exposure	310	327
Variable Interest Entity, Not Primary Beneficiary | Money Market Funds
Variable Interest Entity [Line Items]
Total Assets		53
Maximum Exposure		62
Variable Interest Entity, Not Primary Beneficiary | Loans Receivable
Variable Interest Entity [Line Items]
Total Assets	1,622	1,370
Maximum Exposure	2,465	2,203
Variable Interest Entity, Not Primary Beneficiary | Restructured Loans [Member]
Variable Interest Entity [Line Items]
Total Assets	2	10
Maximum Exposure	$ 2	$ 12