Name:	fitb_FairValueOptionLoansHeldAsAssets90DaysOrMorePastDueAggregateUnpaidPrincipal
Namespace Prefix:	fitb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

Name:	fitb_FairValueOptionLoansHeldAsAssetsAggregateUnpaidPrincipalBalanceAbstract
Namespace Prefix:	fitb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Loans held as assets for which the fair value option has been elected, this item represents the aggregate unpaid principal balance of those loans that are in nonaccrual status

No definition available.

Name:	fitb_FairValueOptionLoansHeldAsAssetsAmountInNonaccrualStatusAggregateUnpaidPrincipal
Namespace Prefix:	fitb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Fair value portion of loans receivable including mortgage loans held-for-investment and mortgage loans held-for-sale.

No definition available.

Name:	fitb_FairValuePortionLoansReceivableDisclosure
Namespace Prefix:	fitb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Mortgages held for sale for which the fair value option has been elected, this item represents the aggregate unpaid principal amount

No definition available.

Name:	fitb_MortgagesHeldForSaleUnpaidPrincipal
Namespace Prefix:	fitb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

Name:	us-gaap_FairValueOptionLoansHeldAsAssets90DaysOrMorePastDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

Name:	us-gaap_FairValueOptionLoansHeldAsAssetsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

This item represents the aggregate fair value of loans held as assets that are in nonaccrual status for which the fair value option has been elected, if the entity's policy is to recognize interest income separately from other changes in fair value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (e)(2)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

Name:	us-gaap_FairValueOptionLoansHeldAsAssetsAggregateAmountInNonaccrualStatus
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

For loans held as assets for which the fair value option has been elected, this item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of those loans that are 90 days or more past due, in nonaccrual status, or both.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (e)(3)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

Name:	us-gaap_FairValueOptionLoansHeldAsAssetsAggregateDifference
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.