XML 57 R48.htm IDEA: XBRL DOCUMENT
v3.23.2

Derivatives and Hedging Activities - Impact of Client Swap Program that are Not Designated in Accounting Hedges (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Client swap program hedges |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative instruments not designated as hedging instruments, gain (loss), net | $ (926) | $ 0 | $ (900) | $ 0
Other noninterest income | Pay fixed/receive floating swap |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative instruments not designated as hedging instruments, gain (loss), net | 12,612 | 15,865 | (2,409) | 54,202
Other noninterest income | Receive fixed/pay floating swap |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative instruments not designated as hedging instruments, gain (loss), net | $ (13,538) | $ (15,865) | $ 1,509 | $ (54,202)

X
- Definition Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4C Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Name Accounting Standards Codification -Section 50 -Paragraph 4CC -SubTopic 10 -Topic 815 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4CC + Details
Name: | us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480237/815-40-50-5 + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=wfsl_NoninterestIncomeOtherOperatingIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wfsl_InterestRateContractPayFixedReceiveFloatingSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wfsl_InterestRateContractReceiveFixedPayFloatingSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |