Name:	fdef_FairValueInputDiscountRate
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Data Type:	num:percentItemType
Balance Type:	na
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The provisional expenses recorded for impaired financing receivables.

No definition available.

Name:	fdef_ImpairedFinancingReceivablesProvisionalExpenses
Namespace Prefix:	fdef_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Fair value measurement of mortgage servicing rights.

No definition available.

Name:	fdef_MortgageServicingRightsAtFairValue
Namespace Prefix:	fdef_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Fair value of real estate held for sales during the period

No definition available.

Name:	fdef_RealEstateHeldForSaleIncreaseDecreaseInFairValue
Namespace Prefix:	fdef_
Data Type:	xbrli:monetaryItemType
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Reduction in valuation allowance of Mortgage servicing rights.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_FairValueOptionQualitativeDisclosuresRelatedToElectionLineItems
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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

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The cash inflow associated with the collection, including prepayments, of loans receivable issued for financing of goods and services.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

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Data Type:	xbrli:monetaryItemType
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Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancialInstrumentAxis=fdef_RealEstateHeldForSaleMember
Namespace Prefix:
Data Type:	na
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