XML 21 R47.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Covered Assets - Credit Risk Profile by Internally Assigned Grade by Loan Status Designation (Details) (USD $) In Thousands, unless otherwise specified | Mar. 31, 2015 | Sep. 30, 2014
--- | --- | ---
Covered Assets, Loan Status Designation [Line Items] |  |
Total covered loans | $ 159,018 wfsl_LoansAndLeasesReceivableCoveredLoansGross | $ 213,203 wfsl_LoansAndLeasesReceivableCoveredLoansGross
Discount | (21,013)us-gaap_ReceivableWithImputedInterestDiscount | (34,483)us-gaap_ReceivableWithImputedInterestDiscount
Allowance | 0 wfsl_CoveredLoansAllowanceForLosses | (2,244)wfsl_CoveredLoansAllowanceForLosses
Covered loans, net | 138,005 wfsl_LoansAndLeasesReceivableCoveredLoansNetReportedAmount | 176,476 wfsl_LoansAndLeasesReceivableCoveredLoansNetReportedAmount
Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 59,853 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember | 100,161 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember
Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 99,165 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember | 113,042 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember
Single-Family Residential [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 20,750 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember | 23,067 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember
Construction - Speculative [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember
Construction - Custom [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember
Land - Acquisition & Development [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 349 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember | 1,364 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember
Land - Consumer Lot Loans [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 72 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember | 73 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember
Multi-Family [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 903 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember | 6,598 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember
Commercial Real Estate [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 22,967 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | 51,336 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial & Industrial [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 4,383 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember | 5,492 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember
HELOC [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 10,093 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember | 11,777 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember
Consumer [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 336 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 454 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Pool 1 - Construction and Land, Acquisition and Development [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 16,063 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember | 20,261 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember
Pool 2 - Single-Family Residential [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 14,928 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember | 15,964 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember
Pool 3 - Multi-family [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 458 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember | 523 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember
Pool 4 - Home Equity Line of Credit and Other Consumer Loans [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 3,309 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember | 3,977 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember
Pool 5 - Commercial Real Estate [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 59,068 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember | 64,391 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember
Pool 6 - Commercial and Industrial [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 5,339 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember | 7,926 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember
Pass [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Total grade as a % of total net loans | 97.60%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 97.20%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 48,157 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 70,926 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Total grade as a % of total net loans | 80.50%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 70.80%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 59,964 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 64,208 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Single-Family Residential [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 19,975 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 21,311 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Construction - Speculative [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Construction - Custom [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Land - Acquisition & Development [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 349 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 972 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Land - Consumer Lot Loans [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 72 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 73 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Multi-Family [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 903 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 6,598 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Commercial Real Estate [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 14,188 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 26,940 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Commercial & Industrial [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 2,241 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 2,801 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | HELOC [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 10,093 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 11,777 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Consumer [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 336 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 454 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Pool 1 - Construction and Land, Acquisition and Development [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 6,639 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 8,349 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Pool 2 - Single-Family Residential [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 14,700 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 15,585 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Pool 3 - Multi-family [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 49 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 52 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Pool 4 - Home Equity Line of Credit and Other Consumer Loans [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 2,728 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 2,804 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Pool 5 - Commercial Real Estate [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 32,425 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 33,909 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Pass [Member] | Pool 6 - Commercial and Industrial [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 3,423 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember | 3,509 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember
Special Mention [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Total grade as a % of total net loans | 0.20%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0.40%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 115 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Total grade as a % of total net loans | 0.00%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0.10%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 685 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 700 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Single-Family Residential [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Construction - Speculative [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Construction - Custom [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Land - Acquisition & Development [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Land - Consumer Lot Loans [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Multi-Family [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Commercial Real Estate [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 115 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Commercial & Industrial [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | HELOC [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Consumer [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Pool 1 - Construction and Land, Acquisition and Development [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Pool 2 - Single-Family Residential [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Pool 3 - Multi-family [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Pool 4 - Home Equity Line of Credit and Other Consumer Loans [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Pool 5 - Commercial Real Estate [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 685 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 700 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Special Mention [Member] | Pool 6 - Commercial and Industrial [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember
Substandard [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Total grade as a % of total net loans | 2.10%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 2.40%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 11,696 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 29,120 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Total grade as a % of total net loans | 19.50%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 29.10%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 36,782 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 47,609 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Single-Family Residential [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 775 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 1,756 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Construction - Speculative [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Construction - Custom [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Land - Acquisition & Development [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 392 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Land - Consumer Lot Loans [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Multi-Family [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Commercial Real Estate [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 8,779 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 24,281 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Commercial & Industrial [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 2,142 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 2,691 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | HELOC [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Consumer [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Pool 1 - Construction and Land, Acquisition and Development [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 9,424 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 11,912 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Pool 2 - Single-Family Residential [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 228 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 379 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Pool 3 - Multi-family [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 409 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 471 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Pool 4 - Home Equity Line of Credit and Other Consumer Loans [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 581 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 1,173 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Pool 5 - Commercial Real Estate [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 24,224 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 29,782 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Substandard [Member] | Pool 6 - Commercial and Industrial [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 1,916 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember | 3,892 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember
Doubtful [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Total grade as a % of total net loans | 0.10%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0.00%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Total grade as a % of total net loans | 0.00%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0.00%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 1,734 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 525 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Single-Family Residential [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Construction - Speculative [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Construction - Custom [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Land - Acquisition & Development [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Land - Consumer Lot Loans [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Multi-Family [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Commercial Real Estate [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Commercial & Industrial [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | HELOC [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Consumer [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Pool 1 - Construction and Land, Acquisition and Development [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Pool 2 - Single-Family Residential [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Pool 3 - Multi-family [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Pool 4 - Home Equity Line of Credit and Other Consumer Loans [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Pool 5 - Commercial Real Estate [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 1,734 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Doubtful [Member] | Pool 6 - Commercial and Industrial [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember | 525 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember
Loss [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Total grade as a % of total net loans | 0.00%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0.00%wfsl_GradeAsPercentageOfTotalGrossLoans / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Total grade as a % of total net loans | 0.00%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0.00%wfsl_GradeAsPercentageOfTotalGrossLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Single-Family Residential [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Construction - Speculative [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionSpeculativeMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Construction - Custom [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_ConstructionCustomMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Land - Acquisition & Development [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandAcquisitionAndDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Land - Consumer Lot Loans [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_LandConsumerLotLoansMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Multi-Family [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_MultiFamilyHousingPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Commercial Real Estate [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Commercial & Industrial [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_CommercialAndIndustrialLoansMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | HELOC [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_HomeEquityLineOfCreditMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Consumer [Member] | Acquired Non Impaired Assets [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredNonImpairedAssetsMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Pool 1 - Construction and Land, Acquisition and Development [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Pool 2 - Single-Family Residential [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool2SingleFamilyResidentialMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Pool 3 - Multi-family [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool3MultifamilyMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Pool 4 - Home Equity Line of Credit and Other Consumer Loans [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Pool 5 - Commercial Real Estate [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool5CommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember
Loss [Member] | Pool 6 - Commercial and Industrial [Member] | Acquired Impaired Loans [Member] |  |
Covered Assets, Loan Status Designation [Line Items] |  |
Outstanding principal balance of acquired loans | $ 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember | $ 0 wfsl_LoansAndLeasesReceivableCoveredLoans / wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis = wfsl_AcquiredImpairedLoansMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = wfsl_Pool6CommercialandIndustrialMember / us-gaap_InternalCreditAssessmentAxis = wfsl_LossMember

X
- Definition Disclosure of the unamortized amount of the discount on the note or receivable which is deducted from the face amount of the receivable or loan. The discount or premium is the difference between the present value and the face amount. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399 + Details
Name: | us-gaap_ReceivableWithImputedInterestDiscount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | wfsl_CoveredAssetsLoanStatusDesignationLineItems
Namespace Prefix: | wfsl_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Covered Loans, Allowance for Losses + References No definition available. + Details
Name: | wfsl_CoveredLoansAllowanceForLosses
Namespace Prefix: | wfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Grade as Percentage of Total Gross Loans + References No definition available. + Details
Name: | wfsl_GradeAsPercentageOfTotalGrossLoans
Namespace Prefix: | wfsl_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Loans and Leases Receivable, Covered Loans, Gross + References No definition available. + Details
Name: | wfsl_LoansAndLeasesReceivableCoveredLoans
Namespace Prefix: | wfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Loans and Leases Receivable, Covered Loans, Gross + References No definition available. + Details
Name: | wfsl_LoansAndLeasesReceivableCoveredLoansGross
Namespace Prefix: | wfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Loans and Leases Receivable, Covered Loans, Net Reported Amount + References No definition available. + Details
Name: | wfsl_LoansAndLeasesReceivableCoveredLoansNetReportedAmount
Namespace Prefix: | wfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_CommercialAndIndustrialLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_ConstructionCustomMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_ConstructionSpeculativeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_HomeEquityLineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_LandAcquisitionAndDevelopmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_LandConsumerLotLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_MultiFamilyHousingPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_Pool1ConstructionandLandAcquisitionandDevelopmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_Pool2SingleFamilyResidentialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_Pool3MultifamilyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_Pool4HomeEquityLineofCreditandOtherConsumerLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_Pool5CommercialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wfsl_Pool6CommercialandIndustrialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=wfsl_LossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis=wfsl_AcquiredImpairedLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | wfsl_CoveredAssetsStatusOfLoansAcquiredInTransferAxis=wfsl_AcquiredNonImpairedAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |