Variable Interest Entities - Additional Information (Detail) (USD $)										3 Months Ended					3 Months Ended		6 Months Ended
	Jun. 30, 2011		Dec. 31, 2010		Jun. 30, 2010		Jun. 30, 2011 Variable Interest Entity, Primary Beneficiary	Dec. 31, 2010 Variable Interest Entity, Primary Beneficiary	Jun. 30, 2010 Variable Interest Entity, Primary Beneficiary	Dec. 31, 2010 Variable Interest Entity, Primary Beneficiary Home Equity	Dec. 31, 2010 Variable Interest Entity, Primary Beneficiary Automobile Loan Contract	Jun. 30, 2011 Variable Interest Entity, Primary Beneficiary Automobile Loan	Jun. 30, 2010 Variable Interest Entity, Primary Beneficiary Automobile Loan	Jun. 30, 2011 Variable Interest Entity, Primary Beneficiary Fifth Third Community Development Corporation Investments	Jun. 30, 2011 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Jun. 30, 2010 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Jun. 30, 2011 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Jun. 30, 2010 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Dec. 31, 2010 Variable Interest Entity, Not Primary Beneficiary Private Equity Funds	Jun. 30, 2011 Variable Interest Entity, Not Primary Beneficiary Restructured Loans	Dec. 31, 2010 Variable Interest Entity, Not Primary Beneficiary Restructured Loans	Jun. 30, 2010 Variable Interest Entity, Not Primary Beneficiary Restructured Loans	Dec. 31, 2010 Variable Interest Entity, Not Primary Beneficiary Money Market Funds Upper Limit	Jun. 30, 2011 Variable Interest Entity, Not Primary Beneficiary Loans Receivable	Dec. 31, 2010 Variable Interest Entity, Not Primary Beneficiary Loans Receivable	Jun. 30, 2010 Variable Interest Entity, Not Primary Beneficiary Loans Receivable	Jun. 30, 2011 Fifth Third Community Development Corporation Investments Variable Interest Entity, Not Primary Beneficiary	Dec. 31, 2010 Fifth Third Community Development Corporation Investments Variable Interest Entity, Not Primary Beneficiary	Jun. 30, 2010 Fifth Third Community Development Corporation Investments Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Lines of credit										$ 903,000,000	$ 2,700,000,000
Number of seperate transactions in which the Bancorp previously sold loans to an isolated trust and conduits											3
Maximum Exposure														9,000,000	298,000,000	273,000,000	298,000,000	273,000,000	322,000,000	14,000,000	13,000,000	24,000,000					1,282,000,000	1,241,000,000	1,127,000,000
Equity investments, fair value																				0
Equity investments, carrying value																				0
Unfunded commitment amounts															184,000,000	159,000,000	184,000,000	159,000,000	193,000,000	2,000,000	1,000,000	1,000,000		774,000,000	733,000,000	627,000,000
Capital contributions															5,000,000	12,000,000	15,000,000	19,000,000
Credit support	$ 1,370,000,000	[1]	$ 1,515,000,000	[1]	$ 4,322,000,000	[1]	$ 7,000,000	$ 7,000,000	$ 7,000,000		$ 7,000,000	$ 7,000,000	$ 7,000,000										$ 1,000,000

[1] Includes $42, $52, and $74 of cash, $7, $7 and $7 of other short-term investments, $29, $29 and $0 of commercial mortgage loans, $231, $241 and $252 of home equity loans, $424, $648 and $911 of automobile loans, ($11), ($14) and ($16) of ALLL, $4, $7 and $7 of other assets, $8, $12 and $19 of other liabilities and $365, $692 and $996 of long-term debt from consolidated VIEs that are included in their respective captions above at June 30, 2011, December 31, 2010 and June 30, 2010, respectively. See Note 8.