Classifications of Consolidated VIE Assets, Liabilities and Noncontrolling Interest Included in the Bancorp's Consolidated Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Jun. 30, 2012	Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011	Dec. 31, 2010
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Cash and due from banks	$ 2,490	[1]		$ 2,663	[1]	$ 2,348	[1]		$ 2,159
Other short-term investments	1,286	[1]		1,781	[1]	2,028	[1]
Commercial mortgage loans	9,348	[1]		10,138	[1]	10,330	[1]
Home equity	10,238	[1]		10,719	[1]	10,920	[1]
Automobile loans	11,912	[1]		11,827	[1]	11,593	[1]
Allowance for loan and lease losses	(1,925)	[1]	(2,016)	(2,255)	[1]	(2,439)	[1]	(2,614)	(3,004)
Other assets	8,689	[1]		8,863	[1]	9,163	[1]
Total Assets	117,483			116,967		114,905
Other liabilities	3,122	[1]		3,270	[1]	3,372	[1]
Long-term debt	8,127	[1]		9,682	[1]	9,800	[1]
Total liabilities	103,714			103,716		101,847
Noncontrolling interests	51			50		29
Variable Interest Entity, Primary Beneficiary
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Cash and due from banks				30		35
Other short-term investments				7		7
Commercial mortgage loans	50			50		29
Home equity				223		228
Automobile loans				259		334
Allowance for loan and lease losses	(2)			(10)		(10)
Other assets	3			4		3
Total Assets	51			563		626
Other liabilities				4		5
Long-term debt				191		270
Total liabilities				195		275
Noncontrolling interests	51			50		29
Variable Interest Entity, Primary Beneficiary | Home Equity
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Cash and due from banks				5		5
Home equity				223		228
Allowance for loan and lease losses				(5)		(5)
Other assets				1		1
Total Assets				224		229
Long-term debt				22		26
Total liabilities				22		26
Variable Interest Entity, Primary Beneficiary | Automobile Loan
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Cash and due from banks				25		30
Other short-term investments				7		7
Automobile loans				259		334
Allowance for loan and lease losses				(3)		(4)
Other assets				1		1
Total Assets				289		368
Other liabilities				4		5
Long-term debt				169		244
Total liabilities				173		249
Variable Interest Entity, Primary Beneficiary | Fifth Third Community Development Corporation Investments [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Commercial mortgage loans	50			50		29
Allowance for loan and lease losses	(2)			(2)		(1)
Other assets	3			2		1
Total Assets	51			50		29
Noncontrolling interests	$ 51			$ 50		$ 29

[1] Includes $0, $30 and $35 of cash, $0, $7 and $7of other short-term investments, $50, $50 and $29 of commercial mortgage loans, $0, $223 and $228 of home equity loans, $0, $259 and $334 of automobile loans, ($2), ($10) and ($10) of ALLL, $3, $4 and $3 of other assets, $0, $4 and $5 of other liabilities, $0, $191and $270 of long-term debt from consolidated VIEs that are included in their respective captions above at September 30, 2012, December 31, 2011 and September 30, 2011, respectively. See Note 8.