Class settlement escrow deposit

No definition available.

Name:	fitb_ClassSettlementEscrow
Namespace Prefix:	fitb_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Additional payment into escrow for plaintiffs not included in the class action suit

+ References

No definition available.

+ Details

Name:	fitb_NonClassActionEscrow
Namespace Prefix:	fitb_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of the funds paid into the class settlement escrow account have been returned to the control of the defendants through Class Exclusion Takedown Payments

+ References

No definition available.

+ Details

Name:	fitb_PercentageEscrowFundsReturnedDefendants
Namespace Prefix:	fitb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Definition

Number of claims dismissed.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingencyClaimsDismissedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of plaintiffs that have filed claims pertaining to a loss contingency.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingencyNumberOfPlaintiffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The difference between the maximum amount of estimated loss and the amount recorded as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 05

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6395354&loc=d3e12631-108344

+ Details

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

Legal and Regulatory Proceedings - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended			9 Months Ended
	Dec. 31, 2008	Sep. 30, 2014	Dec. 31, 2012	Sep. 30, 2014 Federal Lawsuits	Sep. 30, 2014 State Lawsuits	Sep. 30, 2014 Merchants requesting exclusion from class settlement
Loss Contingencies
Number of alleging violations of ERISA that were dismissed	2
Number of merchants				460	1	7,900
Percentage of funds returned to defendants		25.00%
Class Settlement Escrow			$ 46
Non Class Action Escrow			4
Amount in excess of amounts reserved		$ 103