Name:	fitb_CommercialLoansOnNonaccrualStatus
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Credit risk related contingent features, collateral threshold.

No definition available.

Name:	fitb_CreditRiskRelatedContingentFeaturesCollateralThreshold
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Established threshold impaired loans on accrual status

No definition available.

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

Increase in purchased financial assets with credit deterioration.

No definition available.

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

Increase in reserve for unfunded credit commitments.

No definition available.

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

Loans and leases receivable impaired carrying value.

No definition available.

Name:	fitb_LoansAndLeasesReceivableImpairedCarryingValue
Namespace Prefix:	fitb_
Data Type:	xbrli:monetaryItemType
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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

No definition available.

Name:	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

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

Amount of lessee's right to use underlying asset under operating lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

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Name:	srt_RestatementAxis=fitb_LeasesMember
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Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201613Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: