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Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

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Amortized cost of financing receivable 90 days or more past due and still accruing. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 80
-URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922355-210448

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Financing Receivable, Nonaccrual, Percent of Total Loans

No definition available.

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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=srt_MultifamilyMember
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_CommercialandIndustrialMember
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_LandAcquisitionAndDevelopmentMember
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=srt_SingleFamilyMember
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_LandConsumerLotLoansMember
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Data Type:	na
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
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