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

Line of credit commitments to lend additional funds to debtors owing receivables whose terms have been modified in a troubled debt restructuring.

No definition available.

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

Number Of Customers Provided With Payment Relief, COVID-19

No definition available.

Name:	fitb_NumberOfCustomersProvidedWithPaymentReliefCOVID19
Namespace Prefix:	fitb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Number Of Loans Provided With Payment Deferral, COVID-19

No definition available.

Name:	fitb_NumberOfLoansProvidedWithPaymentDeferralCOVID19
Namespace Prefix:	fitb_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 35
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL49126937-111524

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

- References

No definition available.