Condensed Statement of Income Additional Information (Detail) (USD $) In Billions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010
Dividends [Line Items]
Dividends from Bancorp's banking subsidiary to the Bancorp's non-bank subsidiary	$ 2.0	$ 1.4
Dividend Received From Nonbank Companies And Related Subsidiaries	$ 1.7	$ 1.4

Represents the dividend received bank holding companies and related subsidiaries.

No definition available.

Name:	fitb_DividendReceivedFromBankHoldingCompaniesAndRelatedSubsidiaries
Namespace Prefix:	fitb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration