XML 38 R36.htm IDEA: XBRL DOCUMENT v2.4.1.9

Allowance for Losses on Loans - Loans Collectively and Individually Evaluated for Impairment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	$ 108,700us-gaap_FinancingReceivableAllowanceForCreditLosses	$ 112,347us-gaap_FinancingReceivableAllowanceForCreditLosses	$ 116,741us-gaap_FinancingReceivableAllowanceForCreditLosses
Loans receivable, gross	8,793,428us-gaap_LoansAndLeasesReceivableGrossCarryingAmount	8,669,717us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
Single-Family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	55,495us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	62,763us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	64,184us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Loans receivable, gross	5,619,694us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	5,572,244us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Construction - Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	5,451us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember	6,742us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember	8,407us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember
Loans receivable, gross	152,450us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember	140,060us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember
Construction - Custom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	965us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember	1,695us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember	882us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember
Loans receivable, gross	377,561us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember	385,824us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember
Land - Acquisition & Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	6,671us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember	5,592us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember	9,165us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember
Loans receivable, gross	86,405us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember	80,359us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember
Land - Consumer Lot Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	3,113us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember	3,077us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember	3,552us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember
Loans receivable, gross	106,988us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember	111,130us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember
Multi-Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	4,500us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember	4,248us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember	3,816us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember
Loans receivable, gross	980,706us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember	920,285us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	5,872us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	7,548us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	5,595us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Loans receivable, gross	749,856us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	752,957us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	23,328us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember	16,527us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember	16,614us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember
Loans receivable, gross	453,418us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember	434,088us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember
HELOC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	892us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember	928us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember	1,002us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember
Loans receivable, gross	134,998us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember	134,455us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	2,413us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember	3,227us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember	3,524us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Loans receivable, gross	131,352us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember	138,315us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Loans Collectively Evaluated for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	108,700us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember	112,287us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember
Loans receivable, gross	8,084,922us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember	8,316,874us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember
Allowance as a percentage of outstanding loans and leases	1.40%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember	1.40%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember
Loans Collectively Evaluated for Impairment [Member] | Single-Family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	55,495us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	62,067us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Loans receivable, gross	5,542,825us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	5,487,331us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Allowance as a percentage of outstanding loans and leases	1.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	1.10%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Loans Collectively Evaluated for Impairment [Member] | Construction - Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	5,451us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember	6,682us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember
Loans receivable, gross	87,711us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember	130,901us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember
Allowance as a percentage of outstanding loans and leases	6.20%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember	5.50%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember
Loans Collectively Evaluated for Impairment [Member] | Construction - Custom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	965us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember	1,695us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember
Loans receivable, gross	191,787us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember	385,464us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember
Allowance as a percentage of outstanding loans and leases	0.50%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember	0.50%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember
Loans Collectively Evaluated for Impairment [Member] | Land - Acquisition & Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	6,671us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember	5,592us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember
Loans receivable, gross	66,953us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember	73,999us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember
Allowance as a percentage of outstanding loans and leases	10.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember	7.60%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember
Loans Collectively Evaluated for Impairment [Member] | Land - Consumer Lot Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	3,113us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember	3,077us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember
Loans receivable, gross	91,588us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember	95,684us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember
Allowance as a percentage of outstanding loans and leases	3.40%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember	3.20%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember
Loans Collectively Evaluated for Impairment [Member] | Multi-Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	4,500us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember	4,248us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember
Loans receivable, gross	901,277us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember	911,162us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember
Allowance as a percentage of outstanding loans and leases	0.50%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember	0.50%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember
Loans Collectively Evaluated for Impairment [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	5,872us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	7,548us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Loans receivable, gross	533,593us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	563,534us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Allowance as a percentage of outstanding loans and leases	1.10%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	1.40%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Loans Collectively Evaluated for Impairment [Member] | Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	23,328us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember	17,223us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember
Loans receivable, gross	425,724us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember	421,816us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember
Allowance as a percentage of outstanding loans and leases	5.40%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember	4.60%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember
Loans Collectively Evaluated for Impairment [Member] | HELOC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	892us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember	928us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember
Loans receivable, gross	116,544us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember	114,393us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember
Allowance as a percentage of outstanding loans and leases	0.80%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember	0.90%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember
Loans Collectively Evaluated for Impairment [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	2,413us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember	3,227us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Loans receivable, gross	126,920us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember	132,590us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Allowance as a percentage of outstanding loans and leases	1.90%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember	2.40%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansCollectivelyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Loans Individually Evaluated for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember	60us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember
Loans receivable, gross	119,840us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember	134,736us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember
Allowance as a percentage of outstanding loans and leases	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember
Loans Individually Evaluated for Impairment [Member] | Single-Family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Loans receivable, gross	63,091us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	72,869us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Allowance as a percentage of outstanding loans and leases	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Loans Individually Evaluated for Impairment [Member] | Construction - Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember	60us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember
Loans receivable, gross	7,656us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember	9,159us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember
Allowance as a percentage of outstanding loans and leases	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember	0.70%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember
Loans Individually Evaluated for Impairment [Member] | Construction - Custom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember
Loans receivable, gross	0us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember	360us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember
Allowance as a percentage of outstanding loans and leases	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember
Loans Individually Evaluated for Impairment [Member] | Land - Acquisition & Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember
Loans receivable, gross	3,394us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember	3,833us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember
Allowance as a percentage of outstanding loans and leases	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember
Loans Individually Evaluated for Impairment [Member] | Land - Consumer Lot Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember
Loans receivable, gross	12,856us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember	12,939us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember
Allowance as a percentage of outstanding loans and leases	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember
Loans Individually Evaluated for Impairment [Member] | Multi-Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember
Loans receivable, gross	5,019us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember	6,124us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember
Allowance as a percentage of outstanding loans and leases	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember
Loans Individually Evaluated for Impairment [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Loans receivable, gross	26,217us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	27,802us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Allowance as a percentage of outstanding loans and leases	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Loans Individually Evaluated for Impairment [Member] | Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for probable losses	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember	0us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember
Loans receivable, gross	0us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember	0us-gaap_LoansAndLeasesReceivableGrossCarryingAmount / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember
Allowance as a percentage of outstanding loans and leases	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember	0.00%wfsl_AllowanceAsPercentageOfOutstandingLoansAndLeases / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = wfsl_LoansIndividuallyEvaluatedForImpairmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember
Loans Individually Evaluated for Impairment [Member] | HELOC [Member]
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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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

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