XML 54 R44.htm IDEA: XBRL DOCUMENT
v3.25.1

Allowance for Losses on Loans - Credit Risk Profile Based on Payment Activity (Details) - USD ($) $ in Thousands | Mar. 31, 2025 | Sep. 30, 2024
--- | --- | ---
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 21,122,710 | $ 21,120,107
Commercial loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 12,238,959 | 12,205,420
Commercial loans | Multi-family |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 4,867,340 | 4,556,200
Commercial loans | Commercial real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 3,639,477 | 3,732,155
Commercial loans | Commercial & industrial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 2,384,745 | 2,332,732
Commercial loans | Construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 1,211,336 | 1,424,016
Commercial loans | Land - acquisition & development |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 136,061 | 160,317
Consumer loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 8,883,751 | 8,914,687
Consumer loans | Construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 137,501 | 182,415
Consumer loans | Single-family residential |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 8,264,318 | 8,280,300
Consumer loans | Land - consumer lot loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 101,784 | 108,060
Consumer loans | HELOC |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 288,228 | 269,857
Consumer loans | Consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | 91,920 | 74,055
Performing Loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 21,062,824 | $ 21,050,566
% of Total Loans | 99.70% | 99.70%
Performing Loans | Commercial loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 12,199,162 | $ 12,159,121
% of Total Loans | 99.70% | 99.60%
Performing Loans | Commercial loans | Multi-family |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 4,856,863 | $ 4,537,457
% of Total Loans | 99.80% | 99.60%
Performing Loans | Commercial loans | Commercial real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 3,610,157 | $ 3,705,793
% of Total Loans | 99.20% | 99.30%
Performing Loans | Commercial loans | Commercial & industrial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 2,384,745 | $ 2,332,732
% of Total Loans | 100.00% | 100.00%
Performing Loans | Commercial loans | Construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 1,211,336 | $ 1,422,896
% of Total Loans | 100.00% | 99.90%
Performing Loans | Commercial loans | Land - acquisition & development |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 136,061 | $ 160,243
% of Total Loans | 100.00% | 100.00%
Performing Loans | Consumer loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 8,863,662 | $ 8,891,445
% of Total Loans | 99.80% | 99.70%
Performing Loans | Consumer loans | Construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 136,654 | $ 181,567
% of Total Loans | 99.40% | 99.50%
Performing Loans | Consumer loans | Single-family residential |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 8,245,584 | $ 8,258,812
% of Total Loans | 99.80% | 99.70%
Performing Loans | Consumer loans | Land - consumer lot loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 101,776 | $ 108,060
% of Total Loans | 100.00% | 100.00%
Performing Loans | Consumer loans | HELOC |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 287,928 | $ 269,261
% of Total Loans | 99.90% | 99.80%
Performing Loans | Consumer loans | Consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 91,720 | $ 73,745
% of Total Loans | 99.80% | 99.60%
Non-Performing Loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 59,886 | $ 69,541
% of Total Loans | 0.30% | 0.30%
Non-Performing Loans | Commercial loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 39,797 | $ 46,299
% of Total Loans | 0.30% | 0.40%
Non-Performing Loans | Commercial loans | Multi-family |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 10,477 | $ 18,743
% of Total Loans | 0.20% | 0.40%
Non-Performing Loans | Commercial loans | Commercial real estate |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 29,320 | $ 26,362
% of Total Loans | 0.80% | 0.70%
Non-Performing Loans | Commercial loans | Commercial & industrial |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 0 | $ 0
% of Total Loans | 0.00% | 0.00%
Non-Performing Loans | Commercial loans | Construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 0 | $ 1,120
% of Total Loans | 0.00% | 0.10%
Non-Performing Loans | Commercial loans | Land - acquisition & development |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 0 | $ 74
% of Total Loans | 0.00% | 0.00%
Non-Performing Loans | Consumer loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 20,089 | $ 23,242
% of Total Loans | 0.20% | 0.30%
Non-Performing Loans | Consumer loans | Construction |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 847 | $ 848
% of Total Loans | 0.60% | 0.50%
Non-Performing Loans | Consumer loans | Single-family residential |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 18,734 | $ 21,488
% of Total Loans | 0.20% | 0.30%
Non-Performing Loans | Consumer loans | Land - consumer lot loans |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 8 | $ 0
% of Total Loans | 0.00% | 0.00%
Non-Performing Loans | Consumer loans | HELOC |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 300 | $ 596
% of Total Loans | 0.10% | 0.20%
Non-Performing Loans | Consumer loans | Consumer |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Amount | $ 200 | $ 310
% of Total Loans | 0.20% | 0.40%

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-5 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 29 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-29 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-5 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-79 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Grade as Percentage of Total Gross Loans + References No definition available. + Details
Name: | wfsl_GradeAsPercentageOfTotalGrossLoans
Namespace Prefix: | wfsl_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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

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

X
- Details
Name: | us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_NonperformingFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |