XML 70 R50.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Loans Receivable - Loans Impaired, Loan Commitments and Loans Serviced (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Sep. 30, 2018 | Sep. 30, 2017
Receivables [Abstract] |  |
Recorded investment in impaired loans | $ 199,545 | $ 251,274
TDRs included in impaired loans | 156,858 | 207,377
Specific reserves on impaired loans | 517 | 126
Average balance of impaired loans for year ended | 228,398 | 274,530
Interest income from impaired loans for year ended | 10,232 | 11,736
Outstanding fixed-rate origination commitments | 400,426 | 425,130
Gross loans serviced for others | $ 77,958 | $ 77,119

X
- Definition Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Reflects the amount of the write-down related to a troubled debt restructuring. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivablesImpairedTroubledDebtRestructuringWriteDown
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_ReceivablesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financing Receivable, Average Balance of Impaired Loans + References No definition available. + Details
Name: | wfsl_FinancingReceivableAverageBalanceOfImpairedLoans
Namespace Prefix: | wfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Loans and Leases Receivable, Loan Origination Commitments Outstanding + References No definition available. + Details
Name: | wfsl_LoansAndLeasesReceivableLoanOriginationCommitmentsOutstanding
Namespace Prefix: | wfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Loans Serviced for Others + References No definition available. + Details
Name: | wfsl_LoansServicedForOthers
Namespace Prefix: | wfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Recorded investment in impaired loans + References No definition available. + Details
Name: | wfsl_RecordedInvestmentInImpairedLoans
Namespace Prefix: | wfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant