Vesting of restricted stock and early exercised stock options Vesting Of Restricted Stock And Early Exercised Stock Options Vesting Of Restricted Stock And Early Exercised Stock Options Sales of marketable securities Proceeds from Sale of Debt Securities, Available-for-Sale Accrued expenses and other current liabilities Accrued Liabilities, Current Statistical Measurement [Domain] Statistical Measurement [Domain] Total current assets Assets, Current Schedule of Financial Instruments, Assets, and Liabilities Not Recorded at Fair Value Fair Value Disclosure of Asset and Liability Not Measured at Fair Value [Table Text Block] Research and development Research and Development Expense Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Vesting of early exercised stock options Adjustments To Additional Paid In Capital, Early Vesting Of Stock Options Adjustments To Additional Paid In Capital, Early Vesting Of Stock Options Expiration period (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period Revenue from Contract with Customer [Abstract] Total Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value Supplemental cash flow disclosures Supplemental Cash Flow Information [Abstract] Award Type [Domain] Award Type [Domain] Beginning balance (in shares) Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Other income (expense), net Other Nonoperating Income (Expense) Entity Filer Category Entity Filer Category Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Restructuring Type [Axis] Restructuring Type [Axis] Statement [Table] Statement [Table] Investments, Debt and Equity Securities [Abstract] Current Fiscal Year End Date Current Fiscal Year End Date Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Stock repurchase program, authorized amount Stock Repurchase Program, Authorized Amount Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations Repurchase of common stock (in shares) Stock Repurchased During Period, Shares Number of employees impacted Restructuring and Related Cost, Number of Positions Eliminated Estimated Fair Value Cash Equivalents, Fair Value Disclosure And Debt Securities, Available-For-Sale, Current Cash Equivalents, Fair Value Disclosure And Debt Securities, Available-For-Sale, Current Cash Equivalents and Marketable Securities Cash, Cash Equivalents, and Marketable Securities [Text Block] Accounts payable Accounts Payable, Current Exercisable, weighted average remaining contractual term (years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Expected volatility, minimum (as a percent) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum Corporate bonds Corporate bonds Corporate Debt Securities [Member] Commitments and contingencies (Note 6) Commitments and Contingencies RSUs 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 Exercisable (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Loan agreement, terms (in years) Loans Receivable, Terms Loans Receivable, Terms Asset-backed securities Asset-Backed Securities [Member] Fixed interest rate (as percent) Loans Receivable, Fixed Interest Rate Loans Receivable, Fixed Interest Rate Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities Vested or expected to vest, aggregate intrinsic value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Exercisable, aggregate intrinsic value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value Proceeds from issuance of common stock under employee stock purchase plan Proceeds from Issuance of Common Stock Class of Stock [Axis] Class of Stock [Axis] Geographical [Axis] Geographical [Axis] Marketable securities Estimated Fair Value Debt Securities, Available-for-Sale, Current Income Taxes Income Tax Disclosure [Text Block] Description of Business Business Description and Basis of Presentation [Text Block] Expected dividend yield (as a percent) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate Depreciation and amortization Depreciation, Depletion and Amortization Financial liabilities Financial Liabilities Fair Value Disclosure Current liabilities: Liabilities, Current [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Marketable securities: Debt Securities, Available-for-Sale, Amortized Cost [Abstract] Total stockholders’ equity Balance at beginning of period Balance at end of period Equity, Attributable to Parent Subsequent Event Type [Domain] Subsequent Event Type [Domain] 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] Commercial paper Commercial Paper [Member] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Options forfeited and expired (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Net loss per share attributable to Class A and Class B common stockholders, diluted (in USD per share) Earnings Per Share, Diluted Employee and Non-employee Stock Option Employee And Non-employee Stock Option [Member] Employee And Non-employee Stock Option Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Accounts receivable, net of allowance of $380 and $385 as of March 31, 2024 and December 31, 2023, respectively Accounts Receivable, after Allowance for Credit Loss, Current Revenue recognized from contract with customer Contract with Customer, Liability, Revenue Recognized Vested or expected to vest (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Expected term (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term Level 3 Fair Value, Inputs, Level 3 [Member] Subsequent Events [Abstract] Subsequent Events [Abstract] Loss before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Beginning balance (in shares) Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Amortized Cost Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract] Issuance of common stock upon exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Trading Symbol Trading Symbol Restructuring Plan [Domain] Restructuring Plan [Domain] Options granted (in USD per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Conversion from Class B to Class A common stock (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Options granted, weighted average grant date fair value (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Level 2 Fair Value, Inputs, Level 2 [Member] Net loss Net loss Net loss Net Income (Loss) Total current liabilities Liabilities, Current Fair Value Disclosures [Abstract] Entity Emerging Growth Company Entity Emerging Growth Company Due after one to four years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Schedule of Cash and Cash Equivalents Schedule of Cash and Cash Equivalents [Table Text Block] Loan to Opportunity Finance Network Loan To Opportunity Finance Network Loan To Opportunity Finance Network Common stock retired (in shares) Treasury Stock, Shares, Retired Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] ESPP Employee Stock [Member] Repurchase of common stock Stock Repurchased During Period, Value Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Stockholders’ equity: Equity, Attributable to Parent [Abstract] Unrealized Loss Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Issuance of common stock upon exercise of stock options (in shares) Options exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Document Fiscal Period Focus Document Fiscal Period Focus Schedule of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Vesting period (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period 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 Stock-based compensation Share-Based Payment Arrangement, Noncash Expense Class B Common Stock Common Class B [Member] Schedule of Revenue Disaggregated by Geography Revenue from External Customers by Geographic Areas [Table Text Block] Number of Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Other Commitments [Table] Other Commitments [Table] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Common Stock Common Stock [Member] Options exercised (in USD per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Level 1 Fair Value, Inputs, Level 1 [Member] City Area Code City Area Code Entity Address, Postal Zip Code Entity Address, Postal Zip Code Carrying Amount Reported Value Measurement [Member] Net Loss Per Share Attributable to Common Stockholders Earnings Per Share [Text Block] Income Statement Location [Domain] Income Statement Location [Domain] Goodwill Goodwill Estimated Fair Value Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value [Abstract] Equity Components [Axis] Equity Components [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Accrued expenses and other liabilities Increase (Decrease) in Accrued Liabilities Unrealized Loss Cash Equivalents, At Carrying Value And Debt Securities, Available-For-Sale, Unrealized Loss Cash Equivalents, At Carrying Value And Debt Securities, Available-For-Sale, Unrealized Loss Certificates of deposit Certificates of Deposit [Member] Document Fiscal Year Focus Document Fiscal Year Focus Geographical [Domain] Geographical [Domain] Measurement Basis [Axis] Measurement Basis [Axis] Options granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Entity Small Business Entity Small Business Minimum Minimum [Member] Local Phone Number Local Phone Number Accounts receivable, net Increase (Decrease) in Accounts Receivable Property and equipment, net Property, Plant and Equipment, Net Fair Value Measurement [Domain] Fair Value Measurement [Domain] Schedule of Stock Option Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Measurement Frequency [Axis] Measurement Frequency [Axis] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Assets Assets [Abstract] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Operating lease liabilities, non-current Operating Lease, Liability, Noncurrent Schedule of Investments Classified by Contractual Maturity Date Investments Classified by Contractual Maturity Date [Table Text Block] Unvested RSUs Restricted Stock Units (RSUs) [Member] Operating lease liabilities Increase (Decrease) in Operating Lease Liability Tax withholdings on release of restricted stock units Payment, Tax Withholding, Share-Based Payment Arrangement U.S. Treasury securities US Treasury Securities [Member] Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Schedule of Fair Value on Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Income Statement Location [Axis] Income Statement Location [Axis] Accumulated Deficit Retained Earnings [Member] Schedule of Stock-based Compensation Expense Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Accretion of investments Accretion (Amortization) of Discounts and Premiums, Investments Total liabilities and stockholders’ equity Liabilities and Equity The 2021 Plan The 2021 Plan [Member] The 2021 Plan Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost Other assets Other Assets, Noncurrent Risk-free interest rate (as a percent) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Net loss per share attributable to Class A and Class B common stockholders, basic (in USD per share) Earnings Per Share, Basic Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Cash equivalents: Cash Equivalents, at Carrying Value [Abstract] Issuance of common stock under employee stock purchase plan Stock Issued During Period, Value, Employee Stock Purchase Plan Accounting Policies [Abstract] Accounting Policies [Abstract] Unvested early exercised stock options subject to repurchase Unvested Early Exercised Stock Options Subject To Repurchase [Member] Unvested Early Exercised Stock Options Subject To Repurchase Unrealized Gain Cash Equivalents, At Carrying Value And Debt Securities, Available-For-Sale, Unrealized Gain Cash Equivalents, At Carrying Value And Debt Securities, Available-For-Sale, Unrealized Gain Risk-free interest rate, Maximum (as a percent) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum Expected volatility, maximum (as a percent) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum Intrinsic value of options exercised Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value Net loss attributable to common stockholders, diluted Net Income (Loss) Available to Common Stockholders, Diluted Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Schedule of Available-For-Sale of Securities Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Entity Address, City or Town Entity Address, City or Town Change in unrealized gain (loss) on available-for-sale marketable securities Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Research and development Research and Development Expense [Member] Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Operating lease right-of-use assets Increase (Decrease) In Operating Lease, Right-Of-Use Asset Increase (Decrease) In Operating Lease, Right-Of-Use Asset Vested or expected to vest (years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Potentially dilutive securities (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Award Type [Axis] Award Type [Axis] Schedule of Cash and Cash Equivalents [Table] Schedule of Cash and Cash Equivalents [Table] RSUs granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Plan Name [Domain] Plan Name [Domain] Document Quarterly Report Document Quarterly Report Minimum proportion of fair market value of stock options granted to grantees that own more than 10% of voting power (as a percent) Share-Based Compensation Arrangement By Share-Based Payment Award, Minimum Proportion Of Fair Market Value Of Stock Options Granted To Grantees That Own More Than Ten Percent Of Voting Power, Percent Share-Based Compensation Arrangement By Share-Based Payment Award, Minimum Proportion Of Fair Market Value Of Stock Options Granted To Grantees That Own More Than Ten Percent Of Voting Power, Percent Restructuring charges Restructuring Charges Purchases of property and equipment not yet settled Capital Expenditures Incurred but Not yet Paid Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Document Transition Report Document Transition Report General and administrative General and Administrative Expense [Member] Options outstanding, weighted average remaining contractual term (years) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Stock repurchase program, remaining authorized repurchase amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Use of Estimates Use of Estimates, Policy [Policy Text Block] Accounts payable Increase (Decrease) in Accounts Payable Common stock authorized (in shares) Common Stock, Shares Authorized Marketable securities Debt Securities, Available-for-Sale Document Information [Table] Document Information [Table] Entity File Number Entity File Number Total Cash Equivalents, At Carrying Value And Debt Securities, Available-For-Sale, Amortized Cost [Abstract] Cash Equivalents, At Carrying Value And Debt Securities, Available-For-Sale, Amortized Cost Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Restricted Stock Unit Activity Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Operating lease liabilities, current Operating Lease, Liability, Current 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] Unrealized Gain Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Issuance of common stock under employee stock purchase plan (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Entity Shell Company Entity Shell Company Risk-free interest rate, Minimum (as a percent) Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum 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] Significant Accounting Policies and Recently Issued Accounting Pronouncements Not Yet Adopted New Accounting Pronouncements, Policy [Policy Text Block] Due within one year Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Average cost per share (in USD per share) Shares Acquired, Average Cost Per Share Counterparty Name [Domain] Counterparty Name [Domain] Cash, cash equivalents, and restricted cash at beginning of period Cash, cash equivalents, and restricted cash at end of period Total cash, cash equivalents, and restricted cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Interest income Investment Income, Interest Bad debt expense Accounts Receivable, Credit Loss Expense (Reversal) Additional paid-in capital Additional Paid in Capital 12 Months or Greater , Fair Value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Common stock issued (in shares) Common Stock, Shares, Issued Stock repurchase program, authorized increase amount Stock Repurchase Program, Increase Amount Stock Repurchase Program, Increase Amount Note receivable Notes Receivable, Fair Value Disclosure RSUs vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Cost Reduction Plan Cost Reduction Plan [Member] Cost Reduction Plan Total Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Deferred revenue Contract with Customer, Liability, Current Schedule of Assumptions Used to Calculate Fair Value of Stock Option Grants Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] RSUs forfeited (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 Security Exchange Name Security Exchange Name Document Information [Line Items] Document Information [Line Items] Restructuring Plan [Axis] Restructuring Plan [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Financial assets Total cash equivalents and marketable securities Assets, Fair Value Disclosure Gross Unrealized Loss Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Proceeds from exercise of stock options Proceeds from Stock Options Exercised Statement of Comprehensive Income [Abstract] Loans agreement, maximum lending capacity Loans Receivable, Maximum Lending Capacity Loans Receivable, Maximum Lending Capacity Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Outstanding stock options Restricted Stock Units Employee Stock Option [Member] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table] Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current RSUs forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Class A Common Stock Common Class A [Member] Unrecognized stock-based compensation expense, expected period of recognition (in years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Total costs and expenses Costs and Expenses Maximum Maximum [Member] Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Unrecognized stock-based compensation expense Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Amortized Cost Cash Equivalents, at Carrying Value Document Type Document Type Fair value of common stock per share (in USD per share) Share Price Options outstanding, aggregate intrinsic value Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Entity Address, Address Line One Entity Address, Address Line One Entity Registrant Name Entity Registrant Name Tax withholdings on release of restricted stock units Adjustment To Additional Paid In Capital, Tax Withholdings On Release Of Awards Adjustment To Additional Paid In Capital, Tax Withholdings On Release Of Awards Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Subsequent Event [Table] Subsequent Event [Table] Cost of revenue Cost of Sales [Member] Employee Severance Employee Severance [Member] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Other Other Noncash Income (Expense) Purchases of marketable securities Payments to Acquire Debt Securities, Available-for-Sale Document Period End Date Document Period End Date Weighted Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Exercisable (in USD per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Accounts receivable, allowance for credit loss Accounts Receivable, Allowance for Credit Loss, Current Entity Central Index Key Entity Central Index Key Subsequent Event Subsequent Event [Member] Minimum threshold of voting power (as a percent) Share-Based Compensation Arrangement By Share-Based Payment Award, Threshold, Minimum Proportion Of Voting Power Share-Based Compensation Arrangement By Share-Based Payment Award, Threshold, Minimum Proportion Of Voting Power Restricted cash, non-current Restricted Cash, Noncurrent Stock-based compensation expense Share-Based Payment Arrangement, Expense Provision for income taxes Income tax expense Income Tax Expense (Benefit) International Non-US [Member] Income Statement [Abstract] Income Statement [Abstract] Costs and expenses: Costs and Expenses [Abstract] Title of 12(b) Security Title of 12(b) Security Fair Value Measurements Fair Value Disclosures [Text Block] Estimated Fair Value Cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Total other comprehensive income (loss) Comprehensive (loss) income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent 12 Months or Greater , Gross Unrealized Loss Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Equity [Abstract] Equity [Abstract] Beginning balance (in USD per share) Ending balance (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 Revenue Revenue from Contract with Customer, Excluding Assessed Tax Income Tax Disclosure [Abstract] Cash and Cash Equivalents [Line Items] Cash and Cash Equivalents [Line Items] Amendment Flag Amendment Flag Stock Options - Grantees Owning >10% of Voting Power Share-based Payment Arrangement, Option, Grantees Owning More Than Ten Percent Of Voting Power [Member] Share-based Payment Arrangement, Option, Grantees Owning More Than Ten Percent Of Voting Power Money market funds Money Market Funds [Member] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Entity Tax Identification Number Entity Tax Identification Number Less than 12 Months , Gross Unrealized Loss Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Alternative [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] Due within one year Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Financial Instrument [Axis] Financial Instrument [Axis] Entity Interactive Data Current Entity Interactive Data Current Common stock purchased (in shares) Treasury Stock, Shares, Acquired Reconciliation of cash, cash equivalents, and restricted cash to the consolidated balance sheets Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract] Repurchase of common stock Payments for Repurchase of Common Stock Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Sales and marketing Selling and Marketing Expense [Member] Common stock retired, amount Treasury Stock, Retired, Cost Method, Amount Weighted average shares used in computing net loss per share attributable to Class A and Class B common stockholders, diluted(in shares) Weighted Average Number of Shares Outstanding, Diluted Non-cash investing and financing activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Increase in number of stock available for grant as a proportion of common stock outstanding (as a percent) Share-based Compensation Arrangement by Share-based Payment Award, Increase In Number Of Shares Available For Grant, Percentage Of Shares Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Increase In Number Of Shares Available For Grant, Percentage Of Shares Outstanding Unrealized Gain Cash And Cash Equivalents, Unrealized Gain Cash And Cash Equivalents, Unrealized Gain Lease liabilities arising from obtaining right-of-use assets Lease Liabilities Arising From Obtaining Right-Of-Use Assets Lease Liabilities Arising From Obtaining Right-Of-Use Assets Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Accumulated deficit Retained Earnings (Accumulated Deficit) Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Deferred Revenue Geographical Information Revenue from Contract with Customer [Text Block] Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Amortized Cost Cash Equivalents, At Carrying Value And Debt Securities, Available-For-Sale, Amortized Cost Cash Equivalents, At Carrying Value And Debt Securities, Available-For-Sale, Amortized Cost Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Additional Paid-in Capital Additional Paid-in Capital [Member] Current assets: Assets, Current [Abstract] Other Commitments [Line Items] Other Commitments [Line Items] Total assets Assets Entity Address, State or Province Entity Address, State or Province Counterparty Name [Axis] Counterparty Name [Axis] Cover [Abstract] Cover [Abstract] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Subsequent Events Subsequent Events [Text Block] Stock-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition United States UNITED STATES Fair Value, Recurring Fair Value, Recurring [Member] Common stock outstanding (in shares) Balance at beginning of period (in shares) Balance at end of period (in shares) Common Stock, Shares, Outstanding Maturities of marketable securities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Other liabilities, non-current Other Liabilities, Noncurrent RSUs 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 Options forfeited or expired (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period Prepayment under share repurchase program Prepayments For Repurchase Of Common Stock Prepayments For Repurchase Of Common Stock 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 Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Common stock, par value (in USD per share) Common Stock, Par or Stated Value Per Share Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Equity Component [Domain] Equity Component [Domain] Net cash provided by investing activities Net Cash Provided by (Used in) Investing Activities Class of Stock [Domain] Class of Stock [Domain] ESPP, purchase price as proportion of common stock price (as a percent) Share-Based Compensation Arrangement by Share-Based Payment Award, Purchase Price of Common Stock, Percent Net loss attributable to common stockholders, basic Net Income (Loss) Available to Common Stockholders, Basic Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Number of Options Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Number of loan disbursement Number Of Loan Disbursements Number Of Loan Disbursements Weighted average shares used in computing net loss per share attributable to Class A and Class B common stockholders, basic (in shares) Weighted Average Number of Shares Outstanding, Basic Entity Current Reporting Status Entity Current Reporting Status Shares issuable pursuant to the ESPP Employee Stock Purchase Plan [Member] Employee Stock Purchase Plan Loss from operations Operating Income (Loss) Total liabilities Liabilities Opportunity Finance Network Opportunity Finance Network [Member] Opportunity Finance Network U.S. Agency bonds Agency Securities [Member] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Common Stock and Stockholders’ Equity Shareholders' Equity and Share-Based Payments [Text Block] Release of restricted stock units (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Forfeited Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Accumulated Other Comprehensive Income AOCI Attributable to Parent [Member] Cost of revenue Cost of Revenue Fair Value Debt Securities, Available-for-Sale, Unrealized Loss Position Shares reserved for issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Measurement Frequency [Domain] Measurement Frequency [Domain] Loan disbursement Loan Disbursement Loan disbursement Loan agreement, lending grand, terms (in months) Loans Receivable, Lending Grand, Terms Loans Receivable, Lending Grand, Terms Statement [Line Items] Statement [Line Items] Plan Name [Axis] Plan Name [Axis] Fair Value Estimate of Fair Value Measurement [Member] Unrealized Loss Cash And Cash Equivalents, Unrealized Loss Cash And Cash Equivalents, Unrealized Loss Vested or expected to vest (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Additional Disclosures Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Subsequent Event [Line Items] Subsequent Event [Line Items] Schedule of Marketable Securities Debt Securities, Available-for-Sale [Table Text Block] Sales and marketing Selling and Marketing Expense Common stock Common Stock, Value, Issued Type of Restructuring [Domain] Type of Restructuring [Domain] Less than 12 Months , Fair Value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months General and administrative General and Administrative Expense Due after one to four years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract]