Summary of the Credit Risk Profile of the Bancorp's Residential Mortgage and Consumer Portfolio Segments by Class Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013
Statement [Abstract]
Reclassification of home equity loans and lines from performing to nonperforming status	$ 46

As a result of the modification of the nonaccrual policy for home equity loans and lines of credit, certain home equity loans and lines of credit were reclassified from performing to nonperforming status.

No definition available.

Name:	fitb_ReclassifiationHomeEquityLoans
Namespace Prefix:	fitb_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration