Commitments, Contingent Liabilities and Guarantees - Additional Information (Detail) (USD $) Share data in Millions, unless otherwise specified										3 Months Ended			6 Months Ended	12 Months Ended							12 Months Ended
	Jun. 30, 2011		Mar. 31, 2011	Dec. 31, 2010		Jun. 30, 2010		Mar. 31, 2010	Dec. 31, 2009	Jun. 30, 2011 Private Mortgage Reinsurance	Dec. 31, 2010 Visa Litigation	Jun. 30, 2010 Visa Litigation	Jun. 30, 2011 Visa Litigation	Dec. 31, 2010 Visa Litigation	Dec. 31, 2009 Visa Litigation	Dec. 31, 2007 Visa Litigation	Dec. 31, 2008 Visa Litigation	Jun. 30, 2011 Visa Litigation Swap	Dec. 31, 2010 Visa Litigation Swap	Jun. 30, 2010 Visa Litigation Swap	Dec. 31, 2009 Visa	Dec. 31, 2008 Visa	Jun. 30, 2011 Other Liabilities	Dec. 31, 2010 Other Liabilities	Jun. 30, 2010 Other Liabilities	Jun. 30, 2011 Standby Letters of Credit	Dec. 31, 2010 Standby Letters of Credit	Jun. 30, 2010 Standby Letters of Credit	Jun. 30, 2011 Standby Letters of Credit Secured Debt	Dec. 31, 2010 Standby Letters of Credit Secured Debt	Jun. 30, 2010 Standby Letters of Credit Secured Debt	Jun. 30, 2011 Variable Rate Demand Note	Dec. 31, 2010 Variable Rate Demand Note	Jun. 30, 2010 Variable Rate Demand Note	Jun. 30, 2011 Variable Rate Demand Note Fifth Third Securities, Inc.	Dec. 31, 2010 Variable Rate Demand Note Fifth Third Securities, Inc.	Jun. 30, 2010 Variable Rate Demand Note Fifth Third Securities, Inc.	Jun. 30, 2011 Lower Limit	Jun. 30, 2011 Upper Limit	Jun. 30, 2011 Residential Mortgage	Dec. 31, 2010 Residential Mortgage	Jun. 30, 2010 Residential Mortgage
Commitments and Contingencies Disclosure [Line Items]
Reserve for unfunded commitments																							$ 197,000,000	$ 227,000,000	$ 254,000,000	$ 4,000,000	$ 10,000,000	$ 6,000,000
Percentage of the total standby letters of credit																										98.00%	99.00%	99.00%	58.00%	54.00%	57.00%
Fifth Third Securities, Inc. (FTS) acted as the remarketing agent to issuers of VRDNs																																3,200,000,000	3,400,000,000	3,100,000,000
Letters of credit	5,096,000,000			5,516,000,000		6,212,000,000																										539,000,000	563,000,000	864,000,000
Purchased VRDNs from the market through FTS, held them in its trading securities portfolio																																	105,000,000	121,000,000
VRDNs remarketed by third parties where the agent has failed to remarket the securities and has instructed the indenture trustee to draw upon letters of credit issued by the Bancorp, approximately, recorded as commercial loans in the Bancorp Condensed Consolidated Balance Sheets	43,436,000,000			43,462,000,000		43,725,000,000																											11,000,000	4,000,000
FTS held VRDN's in its portfolio and classified them as trading securities	217,000,000			294,000,000		270,000,000																													15,000,000	1,000,000	48,000,000
Total outstanding reinsurance coverage	92,000,000			122,000,000		176,000,000
Approximate reserve related to exposures within the reinsurance portfolio	33,000,000			42,000,000		58,000,000
Margin account balance held by the brokerage clearing agent	13,000,000			10,000,000		12,000,000
Fully and unconditionally guaranteed certain long-term borrowing obligations issued by wholly-owned issuing trust entities	2,300,000,000			2,900,000,000		2,800,000,000
Reinsurance coverage ranges of the total PMI coverage																																						5.00%	10.00%
Collateral release amount in the form of investment securities and other assets										5,000,000
Increase (decrease) to the Bancorp's reserve liability										(11,000,000)
Increase (decrease) in the Bancorp's maximum exposure										(27,000,000)
Outstanding balances on residential mortgage loans sold with representation and warranty provisions																																								60,000,000	85,000,000	65,000,000
Outstanding balances on residential mortgage loans sold with credit recourse																																								875,000,000	916,000,000	1,000,000,000
Outstanding balances on residential mortgage loans sold with credit recourse, delinquency rates																																								8.10%	8.70%	6.70%
Credit loss reserve	2,614,000,000	[1],[2]	2,805,000,000	3,004,000,000	[2],[3]	3,693,000,000	[2]	3,802,000,000	3,749,000,000																															20,000,000	16,000,000	20,000,000
Recognized liability equal to the fair value of the indemnification obligation											30,000,000	26,000,000	31,000,000	30,000,000		3,000,000
Recorded share of litigation formally settled by Visa and for probable future litigation settlements															(29,000,000)	169,000,000	71,000,000
Visa IPO, shares of Visa's Class B common stock received																						10.1
Received Class B common shares, carryover basis																						0
Sale of the Class B shares, recognition of the derivative liability and reversal of the net litigation reserve liability resulted in a pre-tax benefit															288,000,000
Sale of the Class B shares, recognition of the derivative liability and reversal of the net litigation reserve liability resulted in an after-tax benefit															187,000,000
Free-standing derivative liability initial fair value with reversal of net Visa litigation reserve													55,000,000					12,000,000	18,000,000	43,000,000
Visa deposited into the litigation escrow account											800,000,000	500,000,000	400,000,000	800,000,000	700,000,000		3,000,000,000
Reduction of liability in cash to the swap counterparty											(35,000,000)	(20,000,000)	(19,000,000)
Share of the Visa escrow account														199,000,000		169,000,000
Completed the sale of its Visa, Inc. Class B shares, proceeds																					$ 300,000,000

[1] Includes $18 related to leverage leases.

[2] 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.

[3] Includes $15 related to leverage leases.