Business Acquisition [Axis] Business Acquisition [Axis] Related Party Transactions [Abstract] Schedule Sensitivity Analysis of Fair Value, Residual Trust Certificates Schedule Sensitivity Analysis of Fair Value, Residual Trust Certificates [Table Text Block] Schedule Sensitivity Analysis of Fair Value, Residual Trust Certificates Total Funding debt Long-Term Debt, Gross Schedule of Available-for-sale Securities with Unrealized Losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Unrealized loss on securities available for sale Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Dividend yield Class Of Warrants Or Rights, Dividend Yield Class Of Warrants Or Rights, Dividend Yield Residual trust certificates, held by third-parties Residual Trust Certificates, Fair Value Disclosure Residual Trust Certificates, Fair Value Disclosure Threshold consecutive trading days Debt Instrument, Convertible, Threshold Consecutive Trading Days Debt Instrument [Axis] Debt Instrument [Axis] Schedule of Indefinite-Lived Intangible Assets Schedule of Indefinite-Lived Intangible Assets [Table Text Block] Commercial agreement assets Commercial Agreement Asset, Net Commercial Agreement Asset, Net Total Property, equipment and software, at cost Property, Plant and Equipment, Gross Other Income and Expenses [Abstract] Investments Investment [Text Block] Additional paid in capital Additional Paid in Capital Share purchase price discount percent Share-Based Compensation Arrangement By Share-Based Payment Award, Share Purchase Price Discount Percent Share-Based Compensation Arrangement By Share-Based Payment Award, Share Purchase Price Discount Percent Fair Value Measurement [Domain] Fair Value Measurement [Domain] Financial Instruments [Domain] Financial Instruments [Domain] Loans held for investment Loans held for investment Financing Receivable, Amortized Cost, Before Allowance for Credit Loss Financing Receivable, Amortized Cost, Before Allowance for Credit Loss Basis spread Debt Instrument, Basis Spread on Variable Rate Depreciation Depreciation 2019 Current period recoveries Financing Receivable, Year Five, Originated, Four Years Before Current Fiscal Year, Recoveries Financing Receivable, Year Five, Originated, Four Years Before Current Fiscal Year, Recoveries Issuance of common stock upon exercise of stock option (in shares) Exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Vesting of restricted stock units (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Government bonds, Non-US Non-US Government Agencies Debt Securities [Member] Non-US Government Agencies Debt Securities Weighted average discount rate Operating Lease, Weighted Average Discount Rate, Percent Initial transfers of financial assets Servicing Liability at Fair Value, Additions Issuance of common stock in acquisition (in shares) Stock Issued During Period, Shares, Acquisitions Within 1 year, fair value Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value Other Other Noncash Income (Expense) Cash paid for income taxes Income Taxes Paid Measurement Input Type [Domain] Measurement Input Type [Domain] Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Minimum percentage of common stock price trigger Minimum Percentage Of Trading Price To Last Reported Sale Price Minimum Percentage Of Trading Price To Last Reported Sale Price Antidilutive common stock equivalents excluded from diluted net loss per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Servicing liability, effect of 50% increase in measurement input Sensitivity Analysis Of Fair Value, Servicing Liability, Effect Of Fifty Percentage Point Increase In Measurement Input Sensitivity Analysis Of Fair Value, Servicing Liability, Effect Of Fifty Percentage Point Increase In Measurement Input Document Information [Line Items] Document Information [Line Items] Performance Fee Liability Performance Fee Liability [Member] Performance Fee Liability Equity Component [Domain] Equity Component [Domain] Discount rate Measurement Input, Discount Rate [Member] Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items] Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Schedule of Sensitivity Analysis of Fair Value, Servicing Assets and Liabilities Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block] Forgiveness of senior secured note Asset Acquisition, Forgiveness Of Long Term Debt Asset Acquisition, Forgiveness Of Long Term Debt Sale of warrants recognized Class Or Warrants Or Rights, Sale Or Warrants Recognized Class Or Warrants Or Rights, Sale Or Warrants Recognized Prior Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year Supplemental Disclosures of Cash Flow Information Supplemental Cash Flow Information [Abstract] Forfeited, expired or cancelled (in USD per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Non-vested RSUs, unrecognized compensation cost Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Plan Name [Domain] Plan Name [Domain] 2021 Current period charge-offs Financing Receivable, Year Three, Originated, Two Years Before Current Fiscal Year, Write Off Financing Receivable, Year Three, Originated, Two Years Before Current Fiscal Year, Write Off Funding debt Borrowings outstanding Long-Term Line of Credit Entity Address, State or Province Entity Address, State or Province Pledged Status [Axis] Pledged Status [Axis] Employee stock purchase plan shares Employee Stock [Member] Weighted Average Remaining Contractual Term Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Within 1 year, amortized cost Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost Expiration period prior to IPO Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Prior To IPO Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Prior To IPO Fair value at beginning of period Fair value at end of period Servicing Asset at Fair Value, Amount Award Type [Axis] Award Type [Axis] Advance rate percentage Debt Instrument, Advance Rate Percentage Debt Instrument, Advance Rate Percentage Trademarks and domains Trademarks And Domains [Member] Trademarks And Domains Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Performance Based Stock Options Performance Based Stock Options [Member] Performance Based Stock Options Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Allowance for credit losses Balance at beginning of period Balance at end of period Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest 2020 Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year Variable Interest Entity, Not Primary Beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] Total liabilities Liabilities Liabilities Weighted average remaining lease term (in years) Operating Lease, Weighted Average Remaining Lease Term Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Cash Flows from Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Revolving facilities Revolving Credit Facility [Member] Document Type Document Type Weighted Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Banking and Thrift, Interest [Abstract] Beginning balance, Non-vested (in USD per share) Ending balance, Non-vested (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Commercial Agreement Asset, Shopify Inc, Warrants Commercial Agreement Asset, Shopify Inc, Warrants [Member] Commercial Agreement Asset, Shopify Inc, Warrants Asset Acquisition [Axis] Asset Acquisition [Axis] ShopBrain ShopBrain [Member] ShopBrain Developed technology Developed Technology Rights [Member] 90 – 119 calendar days past due Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Proceeds from the sale of loans held for investment Proceeds from Sale of Finance Receivables Tranche One Share-Based Payment Arrangement, Tranche One [Member] Schedule of Aggregate Carrying Value of Financial Assets and Liabilities from VIEs Schedule of Assets and Associated Liabilities Accounted for as Secured Borrowings [Table Text Block] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Schedule of Identifiable Intangible Assets Acquired Asset Acquisition [Table Text Block] Debt Disclosure [Abstract] Income Statement Location [Axis] Income Statement Location [Axis] Total current period recoveries Financing Receivable, Recoveries Financing Receivable, Recoveries Securitizations Securitization [Member] Securitization Numerator: Net Income (Loss) Available to Common Stockholders, Basic [Abstract] Amortization of sales and marketing expense Amortization Of Sales and Marketing Expense Amortization Of Sales and Marketing Expense Cost of identifiable intangible assets Fair Value Finite-Lived Intangible Assets Acquired Net Cash Provided by Financing Activities Net Cash Provided by (Used in) Financing Activities Accounting Policies [Abstract] Forfeiture of common stock related to acquisitions (in shares) Common stock remitted back to company (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, Forfeited Fair Value Hierarchy for Financial Assets and Liabilities Not Recorded at Fair Value Fair Value Disclosure of Asset and Liability Not Measured at Fair Value [Table Text Block] Funding costs Interest Expense, Debt Funding debt Line of Credit [Member] Schedule of Loans Held for Investment and Allowance for Credit Loss Financing Receivable, Allowance for Credit Loss [Table Text Block] Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Charge-offs Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff Balance Sheet Components Supplemental Balance Sheet Disclosures [Text Block] Shares purchased by warrants (in shares) Class of Warrant or Right, Number of Securities Called by Warrants or Rights Weighted-average compensation expense recognition period Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Total, unrealized losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Weighted Average Remaining Contractual Term, Vested and exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Schedule of Finite-Lived Intangible Assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Cash Payments to Acquire Businesses, Gross Loan lending terms Financing Receivable, Loan Term Financing Receivable, Loan Term Entity Registrant Name Entity Registrant Name Loans held for investment, net Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss Change in unrealized gain (loss) Effect of foreign currency translation Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss) Issuance of common stock in connection with acquisition Stock Issued, Business Combination Stock Issued, Business Combination Vesting of warrants exercised Warrants Exercised Upon Vesting Warrants Exercised Upon Vesting 2023 Current period net charge-offs Financing Receivable, Year One, Originated, Current Fiscal Year, Write Off (Recoveries), Net Financing Receivable, Year One, Originated, Current Fiscal Year, Write Off (Recoveries), Net Leases [Abstract] Furniture and equipment Furniture And Equipment [Member] Furniture And Equipment Principles of Consolidation Consolidation, Policy [Policy Text Block] Proceeds from debt Proceeds from Debt, Net of Issuance Costs Minimum Minimum [Member] Conversion ratio Debt Instrument, Convertible, Conversion Ratio Entity Emerging Growth Company Entity Emerging Growth Company Common stock, par value (in USD per share) Common Stock, Par or Stated Value Per Share Proceeds from issuance of notes and residual trust certificates by securitization trusts Proceeds from Issuance of Secured Debt Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Technology and data analytics Technology And Data Analytics Expense Technology And Data Analytics Expense Commitments and Contingencies Disclosure [Abstract] Fair Value of Financial Assets and Liabilities Fair Value Disclosures [Text Block] Trading Symbol Trading Symbol Entity File Number Entity File Number Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Marketable Securities [Line Items] Marketable Securities [Line Items] RSUs awarded (in shares) Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Use of Estimates Use of Estimates, Policy [Policy Text Block] Acquisitions Business Combination Disclosure [Text Block] Accounts payable Increase (Decrease) in Accounts Payable Total purchase price Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Aggregate fair value Fair value at beginning of period Fair value at end of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Loans purchased Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Loan Purchased Income Taxes Income Tax Disclosure [Text Block] Amortization expense of warrants sold Class Of Warrants Or Rights, Amortization Expense Class Of Warrants Or Rights, Amortization Expense Credit Facility [Domain] Credit Facility [Domain] Total intangible assets, gross Intangible Assets, Gross (Excluding Goodwill) Basic (in USD per share) Earnings Per Share, Basic Service period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Indefinite-lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets [Axis] 2020 Current period net charge-offs Financing Receivable, Year Four, Originated, Three Years Before Current Fiscal Year, Write Off (Recoveries), Net Financing Receivable, Year Four, Originated, Three Years Before Current Fiscal Year, Write Off (Recoveries), Net Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Entity Interactive Data Current Entity Interactive Data Current Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Proceeds from exercise of common stock options and warrants and contributions to ESPP Proceeds From Stock Options And Warrants Exercised Proceeds From Stock Options And Warrants Exercised Money market funds Money Market Funds [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Schedule of Components and Classification of Stock-based Compensation Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Net Other Comprehensive Loss Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Repurchases of common stock Payments for Repurchase of Common Stock Class of Stock [Axis] Class of Stock [Axis] Funding debt, after year five Long-Term Debt, Maturity, after Year Five 94-96 ITAC Score, 94 to 96 [Member] ITAC Score, 94 to 96 Document Quarterly Report Document Quarterly Report Total assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets One Month London Interbank Offered Rate (LIBOR) One Month London Interbank Offered Rate (LIBOR) [Member] One Month London Interbank Offered Rate (LIBOR) Unpaid principal balance on serviced sold loans Continuing Involvement with Transferred Financial Assets, Principal Amount Outstanding Asset Acquisition [Domain] Asset Acquisition [Domain] Schedule of Revenue by Geographical Area Revenue from External Customers by Geographic Areas [Table Text Block] Accumulated deficit Retained Earnings (Accumulated Deficit) Subsequent changes in fair value Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Subsequent Changes To Fair Value Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Subsequent Changes To Fair Value Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Scenario [Domain] Scenario [Domain] Recurring Fair Value, Recurring [Member] Vested and exercisable (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Transactions with Related Parties Related Party Transactions Disclosure [Text Block] Less than or equal to 1 year, fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Document Fiscal Year Focus Document Fiscal Year Focus Cash Flows from Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Schedule of Credit Quality by ITACs Score Financing Receivable Credit Quality Indicators [Table Text Block] Operating lease expense Operating Lease, Expense Cash paid for acquisition Payments to Acquire Productive Assets Cash received (due to payments or sales) Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlement And Sales Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlement And Sales 2022 Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year Document Information [Table] Document Information [Table] Common stock, outstanding (in shares) Beginning balance, Common Stock (in shares) Ending balance, Common Stock (in shares) Common Stock, Shares, Outstanding Goodwill Beginning balance Ending balance Goodwill Prepaid payroll taxes for stock-based compensation Prepaid Taxes Balance Sheet Related Disclosures [Abstract] Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Income tax expense (benefit) Income Tax Expense (Benefit) Geographical [Domain] Geographical [Domain] Reconciliation to amounts on consolidated balance sheets (as of period end) Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect [Abstract] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Secured Overnight Financing Rate (SOFR) Refund rate Measurement Input, Refund Rate [Member] Measurement Input, Refund Rate Less: Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Common stock Common Stock, Value, Issued Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Other Receivables Other Receivables [Member] Other Receivables Senior Notes Senior Notes [Member] Other assets Other Assets, Miscellaneous Conversion price of redeemable convertible preferred stock (in USD per share) Debt Instrument, Convertible, Conversion Price Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Merchant network revenue Merchant Network [Member] Merchant Network Cash, Cash equivalents and Restricted cash, Beginning of period Cash, Cash Equivalents and Restricted Cash, End of Period Total Cash, Cash Equivalents and Restricted Cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Purchases of loans Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Cash Equivalents Cash Equivalents [Member] Unrealized Gain (Loss) on Investments Unrealized Gain (Loss) on Investments [Table Text Block] Income Statement Location [Domain] Income Statement Location [Domain] Prior current period recoveries Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Recoveries Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Recoveries Number of positions with unrealized losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions Accrued expenses Accrued Liabilities Total, fair value Debt Securities, Available-for-Sale, Unrealized Loss Position Amendment Flag Amendment Flag Remaining lease term Lessee, Operating Lease, Remaining Lease Term Investment Type [Axis] Investment Type [Axis] Weighted Average Remaining Useful Life (in years) Finite-Lived Intangible Assets, Remaining Amortization Period Additions Goodwill, Acquired During Period Residual Trust Certificates Held by Third-Parties in Consolidated VIEs Residual Trust Certificates Held By Third-Parties In Consolidated VIEs [Member] Residual Trust Certificates Held By Third-Parties In Consolidated VIEs Gross Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax 2019 Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year Provision for credit losses Financing Receivable, Excluding Accrued Interest, Credit Loss, Expense (Reversal), Excluding Certain Provisions Financing Receivable, Excluding Accrued Interest, Credit Loss, Expense (Reversal), Excluding Certain Provisions Repurchase Agreement Repurchase Agreement [Member] Repurchase Agreement Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract] Vested and exercisable (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Securitization notes receivable and certificates Securitization Notes Receivable And Certificates [Member] Securitization Notes Receivable And Certificates Depreciation and amortization Depreciation, Depletion and Amortization 2021-Z1 and 2021-Z2 Affirm Asset Securitization Trust 2021-Z1 And 2021-Z2 Notes [Member] Affirm Asset Securitization Trust 2021-Z1 And 2021-Z2 Notes Fair value Total, fair value Debt Securities, Available-for-Sale, Excluding Accrued Interest Prior current period charge-offs Financing Receivable, Originated, More than Five Years Before Current Fiscal Year, Write Off Financing Receivable, Originated, More than Five Years Before Current Fiscal Year, Write Off Contingent Consideration Contingent Consideration [Member] Contingent Consideration Unamortized Discount and Issuance Cost Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Schedule of Interest Income Interest Income and Interest Expense Disclosure [Table Text Block] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Cash paid for operating leases Operating Lease, Payments Available outstanding under stock option plan Stock options, including early exercise of options Share-Based Payment Arrangement, Option [Member] 2019 Current period net charge-offs Financing Receivable, Year Five, Originated, Four Years Before Current Fiscal Year, Write Off (Recoveries), Net Financing Receivable, Year Five, Originated, Four Years Before Current Fiscal Year, Write Off (Recoveries), Net Issuance of common stock upon exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Common stock, authorized (in shares) Common Stock, Shares Authorized Maximum Maximum [Member] Remaining life Debt Instrument, Remaining Life Debt Instrument, Remaining Life Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Loan receivable on nonaccrual status Financing Receivable, 90 Days or More Past Due, Still Accruing Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value 2022 Current period recoveries Financing Receivable, Year Two, Originated, Fiscal Year Before Current Fiscal Year, Recoveries Financing Receivable, Year Two, Originated, Fiscal Year Before Current Fiscal Year, Recoveries Business Acquisition [Line Items] Business Acquisition [Line Items] Measurement Frequency [Domain] Measurement Frequency [Domain] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Line of Credit Facility [Table] Line of Credit Facility [Table] Warrants exercise term Class Of Warrants Or Rights, Exercise Term Class Of Warrants Or Rights, Exercise Term Fast AF, Inc Fast AF, Inc [Member] Fast AF, Inc Purchases of securities available for sale Payments to Acquire Debt Securities, Available-for-Sale Threshold trading days Debt Instrument, Convertible, Threshold Trading Days 2019 Current period charge-offs Financing Receivable, Year Five, Originated, Four Years Before Current Fiscal Year, Write Off Financing Receivable, Year Five, Originated, Four Years Before Current Fiscal Year, Write Off Technology and data analytics Technology And Data Analytics Expense [Member] Technology And Data Analytics Expense Warrants granted for purchase (in shares) Class Of Warrants Or Rights Granted, Common Shares Purchased Class Of Warrants Or Rights Granted, Common Shares Purchased Sublease Income Sublease Income Accounts receivable, net Increase (Decrease) in Accounts Receivable Title of 12(b) Security Title of 12(b) Security Processing and servicing Processing And Servicing Expense Processing And Servicing Expense Notes issued by securitization trusts Notes Payable, Fair Value Disclosure Amortization of discount on loans Accretion Of Discounts, Financing Receivables Accretion Of Discounts, Financing Receivables Less than or equal to 1 year, unrealized losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Segments and Geographical Information Segment Reporting Disclosure [Text Block] Allowance for Credit Losses Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest Other receivables Other Receivables Amortization of premiums on loans Amortization Of Premiums, Financing Receivables Amortization Of Premiums, Financing Receivables Financing Receivable, Allowance for Credit Loss [Table] Financing Receivable, Allowance for Credit Loss [Table] Greater than 1 year, unrealized losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Financing Receivable, Allowance for Credit Loss [Roll Forward] Financing Receivable, Allowance for Credit Loss [Roll Forward] Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Balance at Fair Value Estimate of Fair Value Measurement [Member] Foreign currency translation adjustments Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Interest receivable charged-off, net of recoveries Financing Receivable, Accrued Interest, Writeoff Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Funding debt, remainder of fiscal year Long-Term Debt, Maturity, Remainder of Fiscal Year 2020-A Affirm Asset Securitization Trust 2020-A Notes [Member] Affirm Asset Securitization Trust 2020-A Notes Certificates Of Deposit, Corporate Bonds, US Government Bonds And Commercial Paper Certificates Of Deposit, Corporate Bonds, US Government Bonds And Commercial Paper [Member] Certificates Of Deposit, Corporate Bonds, US Government Bonds And Commercial Paper Threshold percentage of stock price trigger Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger Convertible Senior Notes Convertible Senior Notes [Member] Convertible Senior Notes Basic (in shares) Basic weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Pledged securities Debt Instrument, Collateral Amount Schedule of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Threshold period for delinquent loans past due Financing Receivable, Threshold Period Past Due Class of Warrant or Right [Domain] Class of Warrant or Right [Domain] Accounts receivable, net Accounts Receivable, after Allowance for Credit Loss Accrued interest payable Increase (Decrease) in Interest Payable, Net Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] General and administrative General and Administrative Expense [Member] Corporate bonds Corporate Bond Securities [Member] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Level 3 Fair Value, Inputs, Level 3 [Member] Equity Incentive Plans Share-Based Payment Arrangement [Text Block] Allowance for accounts receivable Accounts Receivable, Allowance for Credit Loss Loans held for sale Financing Receivable, Held For Sale, Fair Value Disclosure Financing Receivable, Held For Sale, Fair Value Disclosure Senior Secured Note Issued To Fast AF, Inc Senior Secured Note Issued To Fast AF, Inc [Member] Senior Secured Note Issued To Fast AF, Inc Loans Held for Investment and Allowance for Credit Losses Financing Receivables [Text Block] Principal repayments and other loan servicing activity Proceeds from Collection of Finance Receivables 90-94 ITAC Score, 90 to 94 [Member] ITAC Score, 90 to 94 Goodwill [Roll Forward] Goodwill [Roll Forward] Principal repayments of funding debt Repayments of Long-Term Lines of Credit Investments, All Other Investments [Abstract] Residual trust certificates, measurement input Residual Trust Certificates, Measurement Input Residual Trust Certificates, Measurement Input Organization, Consolidation and Presentation of Financial Statements [Abstract] Assembled workforce Assembled Workforce [Member] Assembled Workforce Credit Score, ITAC [Domain] Credit Score, ITAC [Domain] Credit Score, ITAC Acquisition, net of cash and restricted cash acquired Payments to Acquire Businesses, Net of Cash Acquired Level 2 Fair Value, Inputs, Level 2 [Member] Warehouse Credit Facilities Warehouse Credit Facilities [Member] Warehouse Credit Facilities Current Fiscal Year End Date Current Fiscal Year End Date Covenant, period prior to final maturity date borrowings can occur Debt Instrument, Covenant, Period Prior To Final Maturity Date Borrowings Can Occur Debt Instrument, Covenant, Period Prior To Final Maturity Date Borrowings Can Occur Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Intangible assets Intangible Assets, Net (Excluding Goodwill) Tranche Two Share-Based Payment Arrangement, Tranche Two [Member] Common stock, stock split Stockholders' Equity Note, Stock Split, Conversion Ratio Transaction costs Asset Acquisition, Transaction Costs Asset Acquisition, Transaction Costs Stock-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] PayBright PayBright [Member] PayBright Schedule of Loans Held for Investment and Allowance for Credit Loss Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Marketable Securities [Table] Marketable Securities [Table] Schedule of Restricted Stock Unit Activity Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Provision for credit losses Financing Receivable, Credit Loss, Expense (Reversal) Accounts payable Accounts Payable Expiration period Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period 2021 Current period recoveries Financing Receivable, Year Three, Originated, Two Years Before Current Fiscal Year, Recoveries Financing Receivable, Year Three, Originated, Two Years Before Current Fiscal Year, Recoveries Servicing asset, effect of 25% increase in measurement input Sensitivity Analysis Of Fair Value, Servicing Asset, Effect Of Twenty Five Percentage Point Increase In Measurement Input Sensitivity Analysis Of Fair Value, Servicing Asset, Effect Of Twenty Five Percentage Point Increase In Measurement Input Processing reserves Cash Deposits, Processing Reserves Cash Deposits, Processing Reserves Fair Value Disclosures [Abstract] Remaining amount available of credit facility Line of Credit Facility, Remaining Borrowing Capacity Prior current period net charge-offs Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Write Off (Recoveries), Net Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Write Off (Recoveries), Net Aggregate Intrinsic Value, Vested and exercisable, and expected to vest Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value No score ITAC Score, No Score [Member] ITAC Score, No Score Credit Facility [Axis] Credit Facility [Axis] Unrealized loss on securities available for sale, net OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Proceeds from maturities and repayments of securities available for sale Proceeds from Sale and Maturity of Debt Securities, Available-for-Sale Equity [Abstract] Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Entity Tax Identification Number Entity Tax Identification Number Number of common stock available for issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Long-lived Assets by Geographic Areas Long-Lived Assets by Geographic Areas [Table Text Block] Early exercise rights liability Share-Based Compensation Arrangement By Share-based Payment Award, Options, Early Exercise Rights Liability Share-Based Compensation Arrangement By Share-based Payment Award, Options, Early Exercise Rights Liability Debt Instrument, Conversion [Domain] Debt Instrument, Conversion [Domain] Debt Instrument, Conversion [Domain] Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Servicing liabilities Servicing Liability 2022 Current period net charge-offs Financing Receivable, Year Two, Originated, Fiscal Year Before Current Fiscal Year, Write Off (Recoveries), Net Financing Receivable, Year Two, Originated, Fiscal Year Before Current Fiscal Year, Write Off (Recoveries), Net Consolidated Entities [Domain] Consolidated Entities [Domain] Collateral held for derivative instruments Derivative Instruments, Collateral Held Derivative Instruments, Collateral Held Net Increase in Cash, Cash Equivalents and Restricted Cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Entity Central Index Key Entity Central Index Key Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Principal repayments of notes issued by securitization trusts Repayments of Secured Debt 2020-Z1 Affirm Asset Securitization Trust 2020-Z1 Notes [Member] Affirm Asset Securitization Trust 2020-Z1 Notes Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Tax withholding on stock-based compensation Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Purchase price Total acquisition date fair value of the consideration transferred Business Combination, Consideration Transferred Measurement Input Type [Axis] Measurement Input Type [Axis] City Area Code City Area Code Less: Discount due to loss on loan purchase commitment Financing Receivable, Unamortized Purchase Discount Financing Receivable, Unamortized Purchase Discount Assets Assets of consolidated VIEs, included in total assets above Assets [Abstract] Subsequent changes in fair value Servicing Liability at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions Schedule of Servicing Liabilities at Fair Value Schedule of Servicing Liabilities at Fair Value [Table Text Block] Servicing assets Servicing Asset Total current period charge-offs Financing Receivable, Write Off Financing Receivable, Write Off Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Commercial Agreement Asset Type [Axis] Commercial Agreement Asset Type [Axis] Commercial Agreement Asset Type Schedule of Servicing Assets at Fair Value Schedule of Servicing Assets at Fair Value [Table Text Block] Senior Pledged Securities Senior Pledged Securities [Member] Senior Pledged Securities Funding debt, year one Long-Term Debt, Maturity, Year One Supplemental Disclosures of Non-Cash Investing and Financing Activities Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Stock-based compensation Share-Based Payment Arrangement, Noncash Expense Weighted-average fair value of employee options granted (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Variable Rate [Axis] Variable Rate [Axis] Purchases of loans held for sale Payments to Purchase Loans Held-for-sale Additions to property, equipment and software Payments to Acquire Property, Plant, and Equipment Asset amortization period Commercial Agreement Asset, Amortization Period Commercial Agreement Asset, Amortization Period Weighted Average Weighted Average [Member] 2024 Finite-Lived Intangible Asset, Expected Amortization, Year One Schedule of Basic and Diluted Net Loss Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Business Description Business Description and Basis of Presentation [Text Block] Payable to third-party loan owners Third Party Loan Owner Payable Third Party Loan Owner Payable Variable Rate Component [Domain] Variable Rate Component [Domain] Variable Rate Component Loans held for sale Financing Receivable, Held-for-Sale Returnly Returnly Technologies, Inc. [Member] Returnly Technologies, Inc. Greater than 1 year, less than or equal to 5 years, amortized cost Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost Available for future grant under stock option plan Share-based Payment Agreement, Option, Future Grant [Member] Share-based Payment Agreement, Option, Future Grant Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Total lease payments Lessee, Operating Lease, Liability, to be Paid 2023 Current period charge-offs Financing Receivable, Year One, Originated, Current Fiscal Year, Write Off Financing Receivable, Year One, Originated, Current Fiscal Year, Write Off Consolidated Variable Interest Entities Variable Interest Entity, Primary Beneficiary [Member] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Funding debt Lines of Credit, Fair Value Disclosure Funding debt, year two Long-Term Debt, Maturity, Year Two Aggregate commitment amount of credit facility Line of Credit Facility, Maximum Borrowing Capacity Income Tax Disclosure [Abstract] Change in operating assets and liabilities: Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract] Credit Score, ITAC [Axis] Credit Score, ITAC [Axis] Credit Score, ITAC Financial Asset, Period Past Due [Domain] Financial Asset, Aging [Domain] Asset Pledged as Collateral Asset Pledged as Collateral [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Investment interest rate Investment Interest Rate Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-Lived Intangible Assets, Major Class Name [Domain] Gross proceeds from matured or redeemed securities Proceeds from Sale and Maturity of Marketable Securities Share-Based Payment Arrangement [Abstract] Long-Lived Assets Long-Lived Assets Schedule of Acquisition Consideration Transferred Schedule of Business Acquisitions, by Acquisition [Table Text Block] Net Loss Net Loss Net Income (Loss) Attributable to Parent Purchases and origination of loans held for investment Payments to Acquire Finance Receivables Other intangibles Other Intangible Assets [Member] Schedule of Funding Debt and Aggregate Future Maturities Schedule of Maturities of Long-Term Debt [Table Text Block] Notes issued by securitization trusts Secured Debt Fed Funds Effective Rate Overnight Index Swap Rate Fed Funds Effective Rate Overnight Index Swap Rate [Member] Scenario [Axis] Scenario [Axis] Total assets Assets, Fair Value Disclosure Vesting rights percentage Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage Leases Lessee, Operating Leases [Text Block] Incremental compensation cost Share-Based Payment Arrangement, Plan Modification, Incremental Cost Plan Name [Axis] Plan Name [Axis] Number of operating segments Number of Operating Segments Servicing liability, measurement input Servicing Liability, Measurement Input 2023 (remaining nine months) Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year 4 – 29 calendar days past due Financial Asset, 4 to 29 Days Past Due [Member] Financial Asset, 4 to 29 Days Past Due Statement of Cash Flows [Abstract] Level 1 Fair Value, Inputs, Level 1 [Member] 2021 Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Denominator: Weighted Average Number of Shares Outstanding, Basic [Abstract] Net Cash Provided by (Used in) Operating Activities Net Cash Provided by (Used in) Operating Activities Commercial agreement warrant expense Increase (Decrease) In Commercial Agreement Assets Increase (Decrease) In Commercial Agreement Assets Derivative instruments Derivative Asset Repayments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Other liabilities Other Liabilities Greater than 1 year, less than or equal to 5 years, fair value Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value Forfeited, expired or cancelled (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Volatility Class Of Warrants Or Rights, Volatility Class Of Warrants Or Rights, Volatility Receivables [Abstract] Liability Class [Axis] Liability Class [Axis] Initial transfers of financial assets Servicing Asset at Fair Value, Additions Certificates of deposit Certificates of Deposit [Member] Commercial agreement asset, gross Commercial Agreement Asset, Gross Commercial Agreement Asset, Gross Geographical [Axis] Geographical [Axis] Accrued expenses and other liabilities Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Maximum Exposure to Losses Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Schedule of Property, Equipment and Software, Net Property, Plant and Equipment [Table Text Block] Prepaid expenses Prepaid Expense Equity exercise taxes payable Share-based Compensation Arrangement by Share-based Payment Award, Exercise Taxes Payable Share-based Compensation Arrangement by Share-based Payment Award, Exercise Taxes Payable Financial Asset, Period Past Due [Axis] Financial Asset, Aging [Axis] Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Debt Debt Disclosure [Text Block] Processing and servicing Processing And Servicing Expense [Member] Processing And Servicing Expense Less than 90 ITAC Score, Less than 90 [Member] ITAC Score, Less than 90 Loss rate Measurement Input, Loss Rate [Member] Measurement Input, Loss Rate Product and Service [Domain] Product and Service [Domain] Commercial agreement term Warrants Exercised, Commercial Agreement Term Warrants Exercised, Commercial Agreement Term Entity Shell Company Entity Shell Company Class B common stock Common Class B [Member] 2021-B Affirm Asset Securitization Trust 2021-B Notes [Member] Affirm Asset Securitization Trust 2021-B Notes 2024 Lessee, Operating Lease, Liability, to be Paid, Year One Common stock issued (in shares) Common stock released form escrow (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Amortization of discount on securities available for sale Amortization Of Discount On Available For Sale Securities Amortization Of Discount On Available For Sale Securities 2027 and thereafter Lessee, Operating Lease, Liability, to be Paid, Year Four and After Year Four Lessee, Operating Lease, Liability, to be Paid, Year Four and After Year Four Financial Instrument [Axis] Financial Instrument [Axis] Funding debt, year three Long-Term Debt, Maturity, Year Three Securities available for sale at fair value Other Investments Changes in fair value of assets and liabilities Gain (Loss) On Changes In Fair Value Of Assets And Liabilities Gain (Loss) On Changes In Fair Value Of Assets And Liabilities Document Period End Date Document Period End Date Expenses on sale of warrants Class Of Warrants Or Rights, Expenses On Grant Date Fair Value On Sale Of Warrants Class Of Warrants Or Rights, Expenses On Grant Date Fair Value On Sale Of Warrants 2021 Current period net charge-offs Financing Receivable, Year Three, Originated, Two Years Before Current Fiscal Year, Write Off (Recoveries), Net Financing Receivable, Year Three, Originated, Two Years Before Current Fiscal Year, Write Off (Recoveries), Net Non-accrued loans held for investment Financing Receivable, Excluding Accrued Interest, Nonaccrual Total Assets Assets Assets Net loss per share attributable to common stockholders for Class A and Class B Earnings Per Share [Abstract] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Residual Certificate Pledged Securities Residual Certificate Pledged Securities [Member] Residual Certificate Pledged Securities Exercised (in USD per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price 2020 Current period recoveries Financing Receivable, Year Four, Originated, Three Years Before Current Fiscal Year, Recoveries Financing Receivable, Year Four, Originated, Three Years Before Current Fiscal Year, Recoveries Profit share liability Commercial Agreement, Profit Share Liability, Fair Value Disclosure Commercial Agreement, Profit Share Liability, Fair Value Disclosure Loss Before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Net Loss per Share Attributable to Common Stockholders Earnings Per Share [Text Block] Servicing Liability at Fair Value, Amount [Roll Forward] Servicing Liability at Fair Value, Amount [Roll Forward] 96+ ITAC Score, Greater than 96 [Member] ITAC Score, Greater than 96 Award Type [Domain] Award Type [Domain] Computer equipment Computer Equipment [Member] Proprietary credit quality score Financing Receivable, ITAC Credit Quality Indicator Financing Receivable, ITAC Credit Quality Indicator Marketable Securities Marketable Securities [Table Text Block] Internally developed software Software Development [Member] Other Other Geographical [Member] Other Geographical Effect of foreign currency translation Goodwill, Foreign Currency Translation Gain (Loss) Entity Address, City or Town Entity Address, City or Town Operating Expenses Operating Expenses [Abstract] Statement of Financial Position [Abstract] Deferred debt issuance costs Debt issuance cost Debt Issuance Costs, Net Funding debt, after year four Long-Term Debt, Maturity, After Year Four Long-Term Debt, Maturity, After Year Four Subsequent changes in fair value Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions Canada CANADA Weighted Average Remaining Contractual Term, Vested and exercisable, and expected to vest Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term Cash collateral and deposits for letters of credit Cash Collateral And Deposits For Letters Of Credit [Member] Cash Collateral And Deposits For Letters Of Credit Securitization and Variable Interest Entities Variable Interest Entity Disclosure [Text Block] Restricted stock units Restricted Stock Units (RSUs) [Member] Conversion Period One Conversion Period One [Member] Conversion Period One Payable to third-party loan owners Increase (Decrease) in Third Party Loan Owner Payable Increase (Decrease) in Third Party Loan Owner Payable Loans held for investment Loans held for investment Non-delinquent loans Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Total current period net charge-offs Financing Receivables, Write Off (Recoveries), Net Financing Receivables, Write Off (Recoveries), Net Other Comprehensive Loss Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Commercial Agreement Asset, Enterprise Partner, Stock Appreciation Rights Commercial Agreement Asset, Enterprise Partner, Stock Appreciation Rights [Member] Commercial Agreement Asset, Enterprise Partner, Stock Appreciation Rights Total Revenue, net Total Revenue, net Revenues Greater than 1 year, fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Amortization of intangible assets Amortization of Intangible Assets Exercise price of warrants (in USD per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Schedule of Goodwill Schedule of Goodwill [Table Text Block] Cash payments for interest expense Interest Paid, Excluding Capitalized Interest, Operating Activities 2026 Lessee, Operating Lease, Liability, to be Paid, Year Three Other Assets Other Assets [Member] Amortization of commercial agreement assets Amortization Of Commercial Agreement Assets Amortization Of Commercial Agreement Assets Servicing income Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset Sales and marketing Selling and Marketing Expense Total stockholders’ equity Beginning balance Ending balance Stockholders' Equity Attributable to Parent Forfeited, expired or cancelled (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Vesting [Domain] Vesting [Domain] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Schedule of Common Stock, Reserved for Future Issuance Schedule Of Common Stock, Reserved For Future Issuance [Table Text Block] Schedule Of Common Stock, Reserved For Future Issuance Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Commercial Agreement Asset Type [Domain] Commercial Agreement Asset Type [Domain] Commercial Agreement Asset Type [Domain] 2026 Finite-Lived Intangible Asset, Expected Amortization, Year Three Summary of Activity for Liabilities With Significant Unobservable Inputs for Fair Value Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Funding debt, year five Long-Term Debt, Maturity, Year Five Reversal of (impairment on) securities available for sale Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Impairment On Securities Available For Sale Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Impairment On Securities Available For Sale Accumulated Deficit Retained Earnings [Member] Non-vested stock options, unrecognized compensation cost Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount Unpaid balance on loans sold with retained servicing rights Loans Sold, Continuing Involvement with Transferred Financial Assets, Principal Amount Outstanding Loans Sold, Continuing Involvement with Transferred Financial Assets, Principal Amount Outstanding Common Stock Common Stock [Member] Number of reportable segments Number of Reportable Segments Schedule of Lease Term and Discount Rate Lease, Cost [Table Text Block] Number of common stock available for issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Contingent consideration liability Contingent consideration Business Combination, Contingent Consideration, Liability Statement [Table] Statement [Table] Vested (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Securitization notes and residual trust certificates, effect of 25% increase (decrease) in measurement input Sensitivity Analysis Of Fair Value, Securitization Notes And Residual Trust Certificates Liability, Effect Of Twenty Five Percentage Point Increase (Decrease) In Measurement Input Sensitivity Analysis Of Fair Value, Securitization Notes And Residual Trust Certificates Liability, Effect Of Twenty Five Percentage Point Increase (Decrease) In Measurement Input Issuance of common stock in acquisition Stock Issued During Period, Value, Acquisitions Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] Schedule of Significant Unobservable Inputs for Level 3 Fair Value Measurement Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Statistical Measurement [Axis] Statistical Measurement [Axis] Common stock issued in escrow, subject to forfeiture (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares, Contingent Consideration Business Acquisition, Equity Interest Issued or Issuable, Number of Shares, Contingent Consideration Adequate compensation Measurement Input, Adequate Compensation [Member] Measurement Input, Adequate Compensation Indefinite-lived intangibles Indefinite-Lived Intangible Assets (Excluding Goodwill) Leasehold improvements Leasehold Improvements [Member] Convertible senior notes, net Convertible Debt, Fair Value Disclosures Equity Components [Axis] Equity Components [Axis] Loans held for investment, net Financing Receivable, Fair Value Disclosure Financing Receivable, Fair Value Disclosure Statement [Line Items] Statement [Line Items] Beginning balance, Non-vested (in shares) Ending balance, Non-vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Variable Rate [Domain] Variable Rate [Domain] Gross Finite-Lived Intangible Assets, Gross Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Repurchases of common stock Stock Repurchased During Period, Value Accumulated Other Comprehensive Income AOCI Attributable to Parent [Member] Second Warrant Shares Second Warrant Shares [Member] Second Warrant Shares Document Transition Report Document Transition Report Local Phone Number Local Phone Number Schedule of Stock Option Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Operating Loss Operating Income (Loss) Financing Receivable, Allowance for Credit Loss [Line Items] Financing Receivable, Allowance for Credit Loss [Line Items] Recently Adopted Accounting Standards and Recent Accounting Pronouncements Not Yet Adopted New Accounting Pronouncements, Policy [Policy Text Block] Warehouse credit facilities Warehouse Credit Facility [Member] Warehouse Credit Facility Equity securities, at cost Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss Accrued expenses and other liabilities Total accrued expenses and other liabilities Accrued Liabilities and Other Liabilities Premiums on loans held for investment Financing Receivable, Unamortized Purchase Premium Financing Receivable, Unamortized Purchase Premium Total liabilities Liabilities, Fair Value Disclosure Repurchases of common stock (in shares) Stock Repurchased During Period, Shares Performance fee liability, measurement input Performance Fee Liability, Measurement Input Performance Fee Liability, Measurement Input Restricted cash Restricted Cash, Fair Value Disclosure Restricted Cash, Fair Value Disclosure Adjustments to reconcile net loss to net cash used in operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Right to purchase shares (in shares) Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Impairment expense on leasehold improvements Impairment, Long-Lived Asset, Held-for-Use Additional Paid-In Capital Additional Paid-in Capital [Member] Document Fiscal Period Focus Document Fiscal Period Focus Net loss per share: Earnings Per Share, Basic [Abstract] Diluted (in shares) Diluted weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Prepayment rate Measurement Input, Prepayment Rate [Member] Interest income on unpaid principal balance Interest and Fee Income, Loans and Leases Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Facilitation of loans Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Facilitation Of Loans Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Facilitation Of Loans Base Rate Base Rate [Member] Marketable Securities Marketable Securities Carrying Amount Reported Value Measurement [Member] Accrued interest receivable Financing Receivable, Accrued Interest, before Allowance for Credit Loss Risk free rate Class Or Warrants Or Rights, Risk Free Rate Class Or Warrants Or Rights, Risk Free Rate Granted (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Summary of Assets and Liabilities Fair Value Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Convertible Debt Convertible Debt [Member] Aggregate Intrinsic Value, Vested and exercisable Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] 2023 Current period recoveries Financing Receivable, Year One, Originated, Current Fiscal Year, Recoveries Financing Receivable, Year One, Originated, Current Fiscal Year, Recoveries Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Vesting of warrants for common stock Adjustments to Additional Paid in Capital, Warrant Issued Net Loss Attributable to Common Stockholders Net Income (Loss) Available to Common Stockholders, Basic Common stock, issued (in shares) Common Stock, Shares, Issued Pledged Status [Domain] Pledged Status [Domain] Additions to property and equipment included in accrued expenses Capital Expenditures Incurred but Not yet Paid Transaction costs Business Combination, Acquisition Related Costs Servicing liability, effect of 25% increase in measurement input Sensitivity Analysis Of Fair Value, Servicing Liability, Effect Of Twenty Five Percentage Point Increase In Measurement Input Sensitivity Analysis Of Fair Value, Servicing Liability, Effect Of Twenty Five Percentage Point Increase In Measurement Input Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Net Cash Provided by (Used in) Investing Activities Net Cash Provided by (Used in) Investing Activities Securitization issued Principal Amount Debt Instrument, Face Amount Proceeds from funding debt Proceeds from Long-Term Lines of Credit Comprehensive Loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Lease termination notice period Lessee, Operating Lease, Termination Notice Period Lessee, Operating Lease, Termination Notice Period Entity Current Reporting Status Entity Current Reporting Status Convertible senior notes, net Convertible Debt Servicing asset, measurement input Servicing Asset, Measurement Input Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Number of vesting conditions Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Number Of Vesting Conditions Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Number Of Vesting Conditions Impairment expense Operating Lease, Impairment Loss Interest income Interest income Interest and Dividend Income, Operating Schedule of Recognized Identified Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Beginning balance (in shares) Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number 30 – 59 calendar days past due Financial Asset, 30 to 59 Days Past Due [Member] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Effect of exchange rate changes on cash, cash equivalents and restricted cash Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations Liabilities: Liabilities of consolidated VIEs, included in total liabilities above Liabilities [Abstract] Property, equipment and software, net Total Property, equipment and software, net Property, Plant and Equipment, Net Schedule of Intangible Assets, Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Subsequent changes in fair value Accrued interest Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Sales and marketing Selling and Marketing Expense [Member] Common stock released from escrow account (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares, Contingent Consideration, Released From Escrow Account Business Acquisition, Equity Interest Issued or Issuable, Number of Shares, Contingent Consideration, Released From Escrow Account Servicing Asset at Fair Value, Amount [Roll Forward] Servicing Asset at Fair Value, Amount [Roll Forward] Forfeited, expired or cancelled (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Total funding debt, net of deferred debt issuance costs Liability component of debt outstanding Long-Term Debt Other (expense) income, net Other Nonoperating Income (Expense) Balance Sheet Location [Axis] Balance Sheet Location [Axis] Economic risk retention Variable Interest Entity, Not Primary Beneficiary, Required Economic Risk Retention Variable Interest Entity, Not Primary Beneficiary, Required Economic Risk Retention Class of Warrant or Right [Axis] Class of Warrant or Right [Axis] Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Proceeds from the sale of loans held for sale Proceeds from Sale of Loans Held-for-sale Class A common stock Common Class A [Member] 2022 Current period charge-offs Financing Receivable, Year Two, Originated, Fiscal Year Before Current Fiscal Year, Write Off Financing Receivable, Year Two, Originated, Fiscal Year Before Current Fiscal Year, Write Off Entity Small Business Entity Small Business Measurement Basis [Axis] Measurement Basis [Axis] Number of common stock issued (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period Revenue Revenues [Abstract] Fair Value Disclosure of Asset and Liability Not Measured at Fair Value [Table] Fair Value Disclosure of Asset and Liability Not Measured at Fair Value [Table] Total amortization expense Finite-Lived Intangible Assets, Net 2020 Employee Stock Purchase Plan 2020 Employee Stock Purchase Plan [Member] 2020 Employee Stock Purchase Plan Restricted cash Restricted Cash Number of Options Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Servicing asset, effect of 50% increase in measurement input Sensitivity Analysis Of Fair Value, Servicing Asset, Effect Of Fifty Percentage Point Increase In Measurement Input Sensitivity Analysis Of Fair Value, Servicing Asset, Effect Of Fifty Percentage Point Increase In Measurement Input Number of votes per share Common Stock, Voting Rights, Number Of Votes Per Share Common Stock, Voting Rights, Number Of Votes Per Share Securitization notes receivable and residual trust certificates Residual Trust Certificates Asset, Fair Value Disclosure Residual Trust Certificates Asset, Fair Value Disclosure Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Other assets Other Assets, Fair Value Disclosure Consolidated Entities [Axis] Consolidated Entities [Axis] Commercial Agreement, Profit Share Liability Commercial Agreement, Profit Share Liability [Member] Commercial Agreement, Profit Share Liability Total Operating Expenses Costs and Expenses 2020 Current period charge-offs Financing Receivable, Year Four, Originated, Three Years Before Current Fiscal Year, Write Off Financing Receivable, Year Four, Originated, Three Years Before Current Fiscal Year, Write Off Debt Instrument [Line Items] Debt Instrument [Line Items] Business Combination and Asset Acquisition [Abstract] Accrued interest payable Interest Payable Class of Stock [Line Items] Class of Stock [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Payment of debt issuance costs Payments of Debt Issuance Costs Government bonds, US US Government Agencies Debt Securities [Member] Operating lease liability Present value of lease liabilities Operating Lease, Liability Amortization of premiums and discounts on loans, net Accretion (Amortization) of Discounts and Premiums, Financing Receivables Accretion (Amortization) of Discounts and Premiums, Financing Receivables Virtual card network revenue Virtual Card Network [Member] Virtual Card Network Other investing cash inflows (outflows) Proceeds From Other Investing Activities Proceeds From Other Investing Activities 2025 Finite-Lived Intangible Asset, Expected Amortization, Year Two 2022-X1 Affirm Asset Securitization Trust 2022-X1 Notes [Member] Affirm Asset Securitization Trust 2022-X1 Notes Granted (in USD per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Total, amortized cost Debt Securities, Available For Sale, Amortized Cost, Including Credit Loss Allowance Debt Securities, Available For Sale, Amortized Cost, Including Credit Loss Allowance Recoveries of charged-off receivables Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery Conversion Period Two Conversion Period Two [Member] Conversion Period Two Schedule of Delinquent Financing Receivables Financing Receivable, Past Due [Table Text Block] Other assets Increase (Decrease) in Other Operating Assets Funding debt, year four Long-Term Debt, Maturity, Year Four Schedule of Length of Contractual Maturities of Securities Available for Sale Investments Classified by Contractual Maturity Date [Table Text Block] Common stock warrants Warrant [Member] Loss on loan purchase commitment Loss On Financing Receivable Commitments To Purchase Loss On Financing Receivable Commitments To Purchase Entity Filer Category Entity Filer Category Certificates Of Deposit, Corporate Bonds, Non-US Government Bonds And Commercial Paper Certificates Of Deposit, Corporate Bonds, Non-US Government Bonds And Commercial Paper [Member] Certificates Of Deposit, Corporate Bonds, Non-US Government Bonds And Commercial Paper Restricted Cash and Cash Equivalents [Axis] Restricted Cash and Cash Equivalents [Axis] United States UNITED STATES Vested and exercisable, and expected to vest thereafter (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price Stock-based compensation expense Total stock-based compensation in operating expenses Share-Based Payment Arrangement, Expense Commitments and contingencies Commitments and Contingencies Security Exchange Name Security Exchange Name Beginning balance (in USD per share) Ending balance (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Merchant relationships Merchant Relationships [Member] Merchant Relationships Unpaid principal balance Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process Useful Life (in years) Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life Total net assets Net Assets Net Assets Revenue Revenue from Contract with Customer, Excluding Assessed Tax Fair value of Class A common stock transferred Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Extension of remaining expected benefit period Commercial Agreement Asset, Amortization Period, Length Of Extension Commercial Agreement Asset, Amortization Period, Length Of Extension 60 – 89 calendar days past due Financial Asset, 60 to 89 Days Past Due [Member] Total common stock reserved for future issuance (in shares) Maximum number of common stock available for issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Cash and Cash Equivalents Cash and Cash Equivalents [Member] Cover [Abstract] 2023 Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year Goodwill impairment loss Goodwill, Impairment Loss Gain on sales of loans Gain on sales of loans Gain (Loss) on Sales of Loans, Net Other assets Total other assets Other Assets Revenue Revenue from Contract with Customer [Text Block] Segment Reporting [Abstract] Investments [Domain] Investments [Domain] Forecast Forecast [Member] Performance fee liability Performance Fee Liability, Fair Value Disclosure Performance Fee Liability, Fair Value Disclosure Payments of tax withholding for stock-based compensation Payment, Tax Withholding, Share-Based Payment Arrangement Total Liabilities and Stockholders’ Equity Liabilities and Equity Offsetting [Abstract] Amortization of debt issuance costs Amortization of Debt Issuance Costs Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Less: Discount due to loss on directly originated loans Financing Receivable, Loss On Self-Organizing Loans Financing Receivable, Loss On Self-Organizing Loans Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Securitization notes and residual trust certificates, effect of 50% increase (decrease) in measurement input Sensitivity Analysis Of Fair Value, Securitization Notes And Residual Trust Certificates Liability, Effect Of Fifty Percentage Point Increase (Decrease) In Measurement Input Sensitivity Analysis Of Fair Value, Securitization Notes And Residual Trust Certificates Liability, Effect Of Fifty Percentage Point Increase (Decrease) In Measurement Input Past due charge-off threshold Financing Receivable, Threshold Period Past Due, Writeoff Less imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Vesting [Axis] Vesting [Axis] Diluted (in USD per share) Earnings Per Share, Diluted Vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Schedule of Other Assets Schedule of Other Assets [Table Text Block] Servicing liabilities Fair value at beginning of period Fair value at end of period Servicing Liability at Fair Value, Amount Amortized Cost Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 2025 Lessee, Operating Lease, Liability, to be Paid, Year Two Total stock-based compensation expense Share-Based Payment Arrangement, Expensed and Capitalized, Amount Period of suspended accrued interest past due Financing Receivable, Threshold Period Past Due, Suspended Accrued Interest Financing Receivable, Threshold Period Past Due, Suspended Accrued Interest Unused commitment fee percentage Line of Credit Facility, Commitment Fee Percentage Vested and exercisable, and expected to vest thereafter (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number Actual performance Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Actual Gain (Loss) Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Actual Gain (Loss) Schedule of Maturities of Lease Liabilities Lessee, Operating Lease, Liability, Maturity [Table Text Block] Debt Instrument, Conversion [Axis] Debt Instrument, Conversion [Axis] Debt Instrument, Conversion Entity Address, Address Line One Entity Address, Address Line One Stock-based compensation included in capitalized internal-use software Capitalized into property, equipment and software, net Share-Based Payment Arrangement, Amount Capitalized 2021-Z1 Affirm Asset Securitization Trust 2021-Z1 Notes [Member] Affirm Asset Securitization Trust 2021-Z1 Notes Product and Service [Axis] Product and Service [Axis] Class of Stock [Domain] Class of Stock [Domain] 2012 Stock Plan Amended And Restated 2012 Stock Plan [Member] Amended And Restated 2012 Stock Plan Interest expense Interest Expense Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Schedule of Long-term Debt Instruments Schedule of Long-Term Debt Instruments [Table Text Block] Variable Rate Component [Axis] Variable Rate Component [Axis] Variable Rate Component Commercial agreement, profit share liability, measurement input Commercial Agreement, Profit Share Liability, Measurement Input Commercial Agreement, Profit Share Liability, Measurement Input 2027 and thereafter Finite-Lived Intangible Asset, Expected Amortization, After Year Three Finite-Lived Intangible Asset, Expected Amortization, After Year Three Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Total intangible assets Intangible Assets, Net (Excluding Goodwill and Not Yet Placed Into Service) Intangible Assets, Net (Excluding Goodwill and Not Yet Placed Into Service) 2023 (remaining nine months) Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year Non-delinquent loans Financial Asset, Not Past Due [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Less: Fair value adjustment on loans acquired through business combination Financing Receivable, Acquired In Business Combination, Fair Value Adjustment Financing Receivable, Acquired In Business Combination, Fair Value Adjustment Commercial paper Commercial Paper [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Senior Notes And Residual Trust Certificates Senior Notes And Residual Trust Certificates [Member] Senior Notes And Residual Trust Certificates General and administrative General and Administrative Expense Impairment of intangible assets Impairment of Intangible Assets (Excluding Goodwill) Schedule of Accrued Expenses and Other Liabilities Schedule Of Accrued Liabilities And Other Liabilities [Table Text Block] Schedule Of Accrued Liabilities And Other Liabilities First Warrant Shares First Warrant Shares [Member] First Warrant Shares Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Statement of Stockholders' Equity [Abstract] Cash Flows from Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] 2021-A Affirm Asset Securitization Trust 2021-A Notes [Member] Affirm Asset Securitization Trust 2021-A Notes Percentage of residual certificates retained Securitized Assets, Percentage Of Residual Certificates Retained Securitized Assets, Percentage Of Residual Certificates Retained Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Gross default rate (2) Default rate Measurement Input, Default Rate [Member] Program profitability Measurement Input, Program Profitability [Member] Measurement Input, Program Profitability