Entity tax identification number Entity Tax Identification Number Rollovers EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Maximum Maximum [Member] Legal Entity [Axis] Legal Entity [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] EBP, Description of Plan [Table] EBP, Description of Plan [Table] Mutual funds Mutual Fund [Member] Investments sold EBP, Investment Sold, Excluding Plan Interest in Master Trust, Selling Price EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Table] Forfeited non-vested account, service break period EBP, Forfeited Nonvested Account, Service Break Period EBP, Forfeited Nonvested Account, Service Break Period Total deductions EBP, Change in Net Asset Available for Benefit, Decrease FAIR VALUE MEASUREMENTS EBP, Investment, Fair Value and NAV [Text Block] Total investments at fair value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Participant annual fee, account balance below threshold EBP, Participant Annual Fee, Account Balance Below Threshold EBP, Participant Annual Fee, Account Balance Below Threshold Level 1 Fair Value, Inputs, Level 1 [Member] EBP, Investment, Fair Value and NAV [Abstract] Assets: EBP, Asset [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] Additions: EBP, Change in Net Asset Available for Benefit, Increase [Abstract] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Table] Payment of Benefits EBP, Payment to Participant [Policy Text Block] Trustee EBP, Trustee [Member] Amendment Flag Amendment Flag Basis of Accounting EBP, Basis of Accounting [Policy Text Block] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] Investment, number of shares EBP, Investment, Number of Shares EBP, Description of Plan and Accounting Change [Abstract] Schedule of Fair Value and NAV EBP, Investment, Fair Value and NAV [Table Text Block] Employer contribution, employer profit sharing, percentage EBP, Employer Contribution, Employer Profit Sharing, Percentage EBP, Employer Contribution, Employer Profit Sharing, Percentage Employer contribution, employer profit sharing, amount EBP, Employer Contribution, Employer Profit Sharing, Amount EBP, Employer Contribution, Employer Profit Sharing, Amount Investments [Domain] Investments [Domain] Use of Estimates EBP, Use of Estimate [Policy Text Block] Participant annual fee, account balance above threshold EBP, Participant Annual Fee, Account Balance Above Threshold EBP, Participant Annual Fee, Account Balance Above Threshold EBP, Related Party and Party-in-Interest [Domain] EBP, Related Party and Party-in-Interest [Domain] FORM 5500, Schedule H, Line 4i - Schedule of Assets (Held at End of Year) EBP, Schedule of Asset Held for Investment [Text Block] Cover [Abstract] RISKS AND UNCERTAINTIES EBP, Risk and Uncertainty [Text Block] Notice period, threshold value EBP, Fair Value, Investment, NAV, Redemption, Notice Period, Threshold Value EBP, Fair Value, Investment, NAV, Redemption, Notice Period, Threshold Value EBP, Related Party and Party-in-Interest [Axis] EBP, Related Party and Party-in-Interest [Axis] Minimum Minimum [Member] Investment Type [Axis] Investment Type [Axis] Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution Participants EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment Interest and dividend income EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment EBP, Description of Plan [Line Items] EBP, Description of Plan [Line Items] Plan number EBP, Plan Number EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Line Items] DESCRIPTION OF PLAN EBP, Description of Plan [Text Block] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Table] Requisite service period, employer profit sharing or employer match contribution EBP, Requisite Service Period, Employer Profit Sharing Or Employer Matching Contribution EBP, Requisite Service Period, Employer Profit Sharing Or Employer Matching Contribution EBP, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Line Items] Contributions EBP, Contribution [Policy Text Block] Automatic deferral rate, annual increase EBP, Participant Contribution, Automatic, Annual Increase Deferral Rate EBP, Participant Contribution, Automatic, Annual Increase Deferral Rate EBP, Schedule of Asset Held for Investment [Abstract] Employer contribution, vesting service period EBP, Employer Contribution Vesting Service Period EBP, Employer Contribution Vesting Service Period EBP, Accounting Policy [Table] EBP, Accounting Policy [Table] Total additions, net EBP, Change in Net Asset Available for Benefit, Increase Investment, Identifier [Axis] Investment, Identifier [Axis] Plan expenses EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Document Information [Line Items] Document Information [Line Items] EBP 001 EBP 001 [Member] EBP 001 EBP, Risk and Uncertainty [Line Items] EBP, Risk and Uncertainty [Line Items] EBP, Risk and Uncertainty [Table] EBP, Risk and Uncertainty [Table] Percentage Vested EBP, Employer Contribution Vesting Percentage EBP, Employer Contribution Vesting Percentage Employer contribution, participant compensation matched, percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, Statement of Change in Net Asset Available for Benefit [Abstract] Level 2 Fair Value, Inputs, Level 2 [Member] EBP, Contribution, Vesting Period [Axis] EBP, Contribution, Vesting Period [Axis] EBP, Contribution, Vesting Period Employer (including Safe Harbor match) EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash EBP, Tax Status [Table] EBP, Tax Status [Table] Net change EBP, Change in Net Asset Available for Benefit, Increase (Decrease) PARTY-IN-INTEREST TRANSACTIONS EBP, Related Party and Party-in-Interest Transactions [Text Block] EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Automatic deferral rate EBP, Participant Contribution, Automatic, Deferral Rate Investments, at fair value: EBP, Investment, Fair Value [Abstract] Dividend income EBP, Change in Net Asset Available for Benefit, Increase from Dividend Income on Investment Benefits paid to participants EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Fair value EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] EBP, Statement of Net Asset Available for Benefit [Abstract] Requisite service hours EBP, Requisite Service Hours EBP, Requisite Service Hours EBP, Accounting Policy [Line Items] EBP, Accounting Policy [Line Items] EBP, Tax Status [Abstract] WaFd, Inc. common stock EBP, Employer, Common Stock Fund [Member] Forfeited non-vested account, number of consecutive breaks in service EBP, Forfeited Nonvested Account, Number Of Consecutive Breaks In Service EBP, Forfeited Nonvested Account, Number Of Consecutive Breaks In Service Schedule of Vesting, Profit Sharing Contributions EBP, Contribution [Table Text Block] 2 EBP, Vesting Period, Year Two [Member] EBP, Vesting Period, Year Two EBP, Contribution, Vesting Period [Domain] EBP, Contribution, Vesting Period [Domain] EBP, Contribution, Vesting Period [Domain] Investment Valuation and Income Recognition EBP, Investment [Policy Text Block] 6 or more EBP, Vesting Period, Year Six Or More [Member] EBP, Vesting Period, Year Six Or More Fair Value, Level 1, Level 2, and Level 3 Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Document Type Document Type PLAN TERMINATION EBP, Plan Termination [Text Block] Entity Central Index Key Entity Central Index Key Collective trusts Common Collective Trust [Member] 5 EBP, Vesting Period, Year Five [Member] EBP, Vesting Period, Year Five Net assets available for benefits: EBP, Net Asset Available for Benefit [Abstract] EBP, Risk and Uncertainty [Abstract] EBP, Tax Status [Line Items] EBP, Tax Status [Line Items] Account balance threshold EBP, Participant Annual Fee, Account Balance Threshold EBP, Participant Annual Fee, Account Balance Threshold EBP, Subsequent Event [Table] EBP, Subsequent Event [Table] Deductions: EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Forfeited non-vested account balance, reduce employer contributions EBP, Forfeited Nonvested Account, Decrease from Employer Contribution 4 EBP, Vesting Period, Year Four [Member] EBP, Vesting Period, Year Four 1 EBP, Vesting Period, Year One [Member] EBP, Vesting Period, Year One 3 EBP, Vesting Period, Year Three [Member] EBP, Vesting Period, Year Three Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] SUMMARY OF ACCOUNTING POLICIES EBP, Summary of Accounting Policy [Text Block] Entity Registrant Name Entity Registrant Name Investments purchased EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost EBP, Subsequent Event [Abstract] SUBSEQUENT EVENTS EBP, Subsequent Event [Text Block] FEDERAL INCOME TAX STATUS EBP, Tax Status [Text Block] EBP, Subsequent Event [Line Items] EBP, Subsequent Event [Line Items] Document Information [Table] Document Information [Table] Notice Period EBP, Fair Value, Investment, NAV, Redemption, Notice Period EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Line Items] Level 3 Fair Value, Inputs, Level 3 [Member] Other receivables EBP, Other Receivable Net assets available for benefits Beginning of the year End of the year EBP, Net Asset Available for Benefit Entity [Domain] Entity [Domain] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Forfeited non-vested account balance EBP, Forfeited Nonvested Account Employer contribution, matching percentage EBP, Employer Contribution, Matching Percentage Net Asset Value Fair Value Measured at Net Asset Value Per Share [Member] EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Line Items] Requisite service period EBP, Requisite Service Period EBP, Requisite Service Period