Accumulated Amortization
Finite-Lived Intangible Assets, Accumulated Amortization
Reorganizations [Abstract]
Award Timing Predetermined
Award Timing Predetermined [Flag]
Entity File Number
Entity File Number
Additional Paid-in Capital
Additional Paid-in Capital [Member]
Tabular List, Table
Tabular List [Table Text Block]
Discount rate
Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Discount Rate
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements
New Accounting Pronouncements, Policy [Policy Text Block]
Loan premium and loan trailing fees recognized
Loan Premium Fees and Loan Trailing Fees
Loan Premium Fees and Loan Trailing Fees
10% adverse change
Sensitivity Analysis of Fair Value, Assets, Impact of 10 Percent Adverse Change in Expected Credit Loss Rates
Sensitivity Analysis of Fair Value, Assets, Impact of 10 Percent Adverse Change in Expected Credit Loss Rates
Schedule of Assets and Liabilities Measured at Fair Value
Fair Value, by Balance Sheet Grouping [Table Text Block]
Other notes receivable
Line Of Credit Receivable, Measurement Input
Line Of Credit Receivable, Measurement Input
Adjustment to Compensation:
Adjustment to Compensation [Axis]
Named Executive Officers, Footnote
Named Executive Officers, Footnote [Text Block]
Revenue
Revenue from Contract with Customer [Text Block]
Financing Receivable Portfolio Segment [Domain]
Financing Receivable Portfolio Segment [Domain]
Schedule of Stock by Class [Table]
Stock, Class of Stock [Table]
Issuance of common stock under employee stock purchase plan (in shares)
Stock Issued During Period, Shares, Employee Stock Purchase Plans
Issuance of common stock upon settlement of restricted stock units (in shares)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures
Adjustment to Compensation, Amount
Adjustment to Compensation Amount
Concentration risk (in percent)
Concentration Risk, Percentage
Other assets
Increase (Decrease) in Other Operating Assets
Consolidation
Consolidation, Policy [Policy Text Block]
Stock-based compensation
Share-Based Payment Arrangement, Noncash Expense
Options issued and outstanding
Options to purchase common stock
Share-Based Payment Arrangement, Option [Member]
Property, Plant and Equipment [Table]
Property, Plant and Equipment [Table]
200 basis point increase
Sensitivity Analysis of Fair Value, Assets, Impact of 200 Basis Point Increase In Discount Rates
Sensitivity Analysis of Fair Value, Assets, Impact of 200 Basis Point Increase In Discount Rates
Loans (at fair value)
Loans (at fair value)
Financing receivable, after allowance for credit loss
Fair value
Financing Receivable, after Allowance for Credit Loss
Antidilutive Securities [Axis]
Antidilutive Securities [Axis]
Total stockholders’ equity
Beginning balance
Ending balance
Net Assets
Equity, Attributable to Parent
Insider Trading Policies and Procedures [Line Items]
Schedule of Property, Equipment, and Software
Property, Plant and Equipment [Table Text Block]
Common stock, authorized (in shares)
Common Stock, Shares Authorized
Hybrid Instruments
Hybrid Instrument [Member]
Shares issued (in shares)
Stock Issued During Period, Shares, New Issues
Liabilities and Stockholders’ Equity
Liabilities and Equity [Abstract]
Cover [Abstract]
2026
Long-term and Short-term Debt, Maturity, Year One
Long-term and Short-term Debt, Maturity, Year One
Maximum
Maximum [Member]
Options exercisable, weighted average exercise price per share (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price
Loans Held-for- Sale
Loan Held For Sale [Member]
Loan Held For Sale
Net Carrying Value
Finite-Lived Intangible Assets, Net
Collateral
Debt Instrument, Collateral Amount
Non-PEO NEO Average Total Compensation Amount
Non-PEO NEO Average Total Compensation Amount
Debt Instrument [Line Items]
Debt Instrument [Line Items]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]
Schedule of Restricted Stock Units and Restricted Stock
Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]
Adjustment to Non-PEO NEO Compensation Footnote
Adjustment to Non-PEO NEO Compensation Footnote [Text Block]
Borrowings
Borrowings
Total borrowings
Debt, Long-Term and Short-Term, Combined Amount
Loans Held in Consolidated Securitization
Loans Held-for-Sale In Consolidated Securitization [Member]
Loans Held-for-Sale In Consolidated Securitization
Forgone Recovery due to Disqualification of Tax Benefits, Amount
Forgone Recovery due to Disqualification of Tax Benefits, Amount
Other assets - Line of credit receivable
Other Assets [Member]
Non-Rule 10b5-1 Arrangement Terminated
Non-Rule 10b5-1 Arrangement Terminated [Flag]
Entity Shell Company
Entity Shell Company
Schedule of Long-Term Debt Instruments [Table]
Schedule of Long-Term Debt Instruments [Table]
Payable to investors
Repayment To Investors
Repayment To Investors
Loss Contingency Nature [Axis]
Loss Contingency Nature [Axis]
Accrued expenses and other liabilities at fair value
Accrued Expenses And Other Liabilities, Fair Value Disclosure
Accrued Expenses And Other Liabilities, Fair Value Disclosure
Statement of Stockholders' Equity [Abstract]
Operating Segments
Operating Segments [Member]
Capitalized stock-based compensation expense
Share-Based Payment Arrangement, Amount Capitalized
Award Timing MNPI Considered
Award Timing MNPI Considered [Flag]
Line of Credit Facility [Table]
Line of Credit Facility [Table]
Interest expense
Interest Expense, Operating
Purchase period
Share-Based Compensation Arrangement By Share-based Payment Award, Purchase Period
Share-Based Compensation Arrangement By Share-based Payment Award, Purchase Period
Settlement of capped calls
Adjustments to Additional Paid in Capital, Settlement Of Capped Calls
Adjustments to Additional Paid in Capital, Settlement Of Capped Calls
Notes receivable and residual certificates (at fair value)
Other Receivables
Schedule of Stock-based Compensation Expense
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]
Document Fiscal Period Focus
Document Fiscal Period Focus
Total payments due
Total
Outstanding borrowings
Beginning balance
Closing balance
Long-Term And Short-Term Debt, Gross
Long-Term And Short-Term Debt, Gross
Purchase of capped calls
Adjustments to Additional Paid in Capital, Purchase Of Capped Calls
Adjustments to Additional Paid in Capital, Purchase Of Capped Calls
Percentage of the last reported sale price
Debt Instrument, Convertible, Maximum Percentage Of Product Of Last Reported Sale Price And Conversion Rate
Debt Instrument, Convertible, Maximum Percentage Of Product Of Last Reported Sale Price And Conversion Rate
Conversion Period Two
Conversion Period Two [Member]
Conversion Period Two
Award Timing Method
Award Timing Method [Text Block]
Schedule of Shares and Warrants Reserved for Issuance
Schedule of Class of Stock and Warrants or Rights [Table Text Block]
Schedule of Class of Stock and Warrants or Rights
Furniture and fixtures
Furniture and Fixtures [Member]
Award Type [Axis]
Award Type [Axis]
Changes in accrued interest
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Changes In Accrued Interest
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Changes In Accrued Interest
Trading Symbol
Trading Symbol
2029
Lessee, Operating Lease, Liability, to be Paid, Year Four
Schedule of Borrowings [Line Items]
Schedule Of Borrowings [Line Items]
Schedule of Borrowings [Line Items]
Loans Held For Sale And Investment
Loans Held For Sale And Investment [Member]
Loans Held For Sale And Investment
Accrued expenses and other liabilities (includes $15,883 and $20,492 at fair value as of December 31, 2024 and September 30, 2025, respectively)
Accrued expenses and other liabilities
Total accrued expenses and other liabilities
Accrued Liabilities and Other Liabilities
Entity Address, City or Town
Entity Address, City or Town
Class of Financing Receivable [Axis]
Class of Financing Receivable [Axis]
Non-PEO NEO Average Compensation Actually Paid Amount
Non-PEO NEO Average Compensation Actually Paid Amount
Loans held-for-investment
Loans Held-For-Investment, Fair Value Disclosure
Loans Held-For-Investment, Fair Value Disclosure
Income Statement Location [Domain]
Statement of Income Location, Balance [Domain]
Restricted stock units outstanding
Unvested RSUs
Restricted Stock Units (RSUs) [Member]
Reclassification of loans
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Reclassification Of Loans
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Reclassification Of Loans
Compensation Actually Paid vs. Other Measure
Compensation Actually Paid vs. Other Measure [Text Block]
Entity Emerging Growth Company
Entity Emerging Growth Company
Beginning balance (in shares)
Ending balance (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number
Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year
Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member]
Unfunded Loan Commitment
Unfunded Loan Commitment [Member]
Risk retention financing facility
Risk Retention Financing Facility [Member]
Risk Retention Financing Facility
Common stock, outstanding (in shares)
Beginning balance (in shares)
Ending balance (in shares)
Common Stock, Shares, Outstanding
Other assets at fair value
Other Assets, Fair Value Disclosure
Schedule of Disaggregation of Revenue by Type of Service
Disaggregation of Revenue [Table Text Block]
Class of Financing Receivable [Domain]
Class of Financing Receivable [Domain]
Weighted average coupon yield
Senior Securitized Loans, Weighted Average Coupon Rate
Senior Securitized Loans, Weighted Average Coupon Rate
Issuance of common stock upon exercise of stock options
Stock Issued During Period, Value, Stock Options Exercised
Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year
Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member]
Schedule of Expected Future Amortization Expense
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]
Thereafter
Long-term and Short-term Debt, Maturity, After Year Five
Long-term and Short-term Debt, Maturity, After Year Five
Number of Shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Effective interest rate
Debt Instrument, Interest Rate, Effective Percentage
Entity Address, Postal Zip Code
Entity Address, Postal Zip Code
Restatement Determination Date
Restatement Determination Date
Provision for income taxes
Income Tax Expense (Benefit)
Customer operations
Customer Operations [Member]
Customer Operations
Basis spread on variable rate
Debt Instrument, Basis Spread on Variable Rate
Collection agency fees
Collection Agency Fees [Member]
Collection Agency Fees
Other assets (includes $107,627 and $229,214 at fair value as of December 31, 2024 and September 30, 2025, respectively)
Other assets (includes $1,864 and $824 at fair value as of December 31, 2024 and September 30, 2025, respectively)
Total other assets
Other Assets
Commissions percentage
Sale Of Stock, Commissions Percentage
Sale Of Stock, Commissions Percentage
Fair value, beginning balance
Fair value, ending balance
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value
Pension Adjustments Service Cost
Pension Adjustments Service Cost [Member]
Fair Value Hierarchy and NAV [Axis]
Fair Value Hierarchy and NAV [Axis]
Fair value adjustments and realized losses on beneficial interests, net
Gain (Loss) On Beneficial Interests
Gain (Loss) On Beneficial Interests
Total property, equipment, and software
Property, Plant and Equipment, Gross
2032 Notes
Twenty Thirty Two Notes [Member]
Twenty Thirty Two Notes
Purchases of loans held-for-sale
Payment for Purchase, Loan, Held-for-Sale
Principal payments received for loans held by consolidated securitization
Proceeds from Securitization, Loan, Held-for-Sale
Reorganization Expenses
Restructuring and Related Activities Disclosure [Text Block]
Compensation Actually Paid vs. Company Selected Measure
Compensation Actually Paid vs. Company Selected Measure [Text Block]
Proceeds from exercise of stock options
Proceeds from Stock Options Exercised
All Trading Arrangements
All Trading Arrangements [Member]
Equity Awards Adjustments, Footnote
Equity Awards Adjustments, Footnote [Text Block]
Total Shareholder Return Vs Peer Group
Total Shareholder Return Vs Peer Group [Text Block]
Redemption price (in percent)
Debt Instrument, Redemption Price, Percentage
Options vested and expected to vest
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term
Beginning balance (in shares)
Ending balance (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number
Commitments and Contingencies Disclosure [Abstract]
Debt Instrument Conversion [Axis]
Debt Instrument Conversion [Axis]
Debt Instrument Conversion
Consolidated securitization
Consolidated Securitization [Member]
Consolidated Securitization
Personal Lending
Personal Lending Segment [Member]
Personal Lending Segment
Unrecognized stock-based compensation expense related to unvested stock options
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount
Net cash provided by (used in) operating activities
Cash Provided by (Used in) Operating Activity, Including Discontinued Operation
Sale of loans
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales
Schedule of Stock Options Fair Value Assumptions
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
Realized gain (loss) on sale of loans, net
Realized Gain (Loss) On Transfer Of Loans, Net
Realized Gain (Loss) On Transfer Of Loans, Net
Total interest income, interest expense, and fair value adjustments, net
Interest income, interest expense, and fair value adjustments, net
Interest Income (Expense), Operating
Equity Valuation Assumption Difference, Footnote
Equity Valuation Assumption Difference, Footnote [Text Block]
PEO Total Compensation Amount
PEO Total Compensation Amount
Depreciation
Depreciation
Long-term Debt, Type [Axis]
Long-Term Debt, Type [Axis]
Options vested and expected to vest, weighted average exercise price per share (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price
Schedule of Level 3 Fair Value Assumptions for Loan Servicing Assets and Liabilities
Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Table Text Block]
Remaining 2025
Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year
Numerator:
Net Income (Loss) Available to Common Stockholders, Diluted [Abstract]
Equity Components [Axis]
Equity Components [Axis]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment [Line Items]
Convertible senior notes
Convertible Debt [Member]
Non-Rule 10b5-1 Arrangement Adopted
Non-Rule 10b5-1 Arrangement Adopted [Flag]
Number of reportable segments
Number of Reportable Segments
At The Market Offering Program
At The Market Offering Program [Member]
At The Market Offering Program
Customer B
Customer B [Member]
Customer B
Total interest income, interest expense, and fair value adjustments, net
Interest Income And Fair Value Adjustment, Net
Interest Income And Fair Value Adjustment, Net
Variable Interest Entities
Variable Interest Entity Disclosure [Text Block]
Entity Address, State or Province
Entity Address, State or Province
Financial Asset, Period Past Due [Domain]
Financial Asset, Aging [Domain]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]
Antidilutive Security, Excluded EPS Calculation [Table]
Loans
Total assets
Fair value of loans held-for-sale and held-for-investment
Loans Receivable, Fair Value Disclosure
Individual:
Individual [Axis]
Beneficial interest assets (at fair value)
Fair value, asset
Fair value of beneficial interest assets
Beneficial Interest Asset
Beneficial Interest Asset
Trailing Fee Liabilities
Trailing Fee Liabilities [Member]
Trailing Fee Liabilities
Maximum Exposure to Losses
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount
Forgone Recovery, Explanation of Impracticability
Forgone Recovery, Explanation of Impracticability [Text Block]
Interest income, interest expense, and fair value adjustments, net:
Revenue Not From Contract With Customer [Abstract]
Revenue Not From Contract With Customer
Hilliard C. Terry III [Member]
Hilliard C. Terry III
Customer A
Customer A [Member]
Customer A
Entity Interactive Data Current
Entity Interactive Data Current
Commitment fee threshold
Line of Credit Facility, Unused Capacity, Commitment Fee Threshold, Percentage Of Borrowing Base
Line of Credit Facility, Unused Capacity, Commitment Fee Threshold, Percentage Of Borrowing Base
Other Contribution Profit/(Loss)
Contribution Profit, Other
Contribution Profit, Other
Loss Contingency, Nature [Domain]
Loss Contingency, Nature [Domain]
HELOCs
Home Equity Line of Credit [Member]
Options exercisable
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value
Schedule Of Beneficial Interest [Line Items]
Schedule Of Beneficial Interest [Line Items]
Schedule Of Beneficial Interest
Platform and referral fees, net
Platform And Referral Fees, Net [Member]
Platform And Referral Fees, Net
Disaggregation of Revenue [Table]
Disaggregation of Revenue [Table]
Notes receivable and residual certificates (at fair value)
Notes Receivable And Residual Certificates [Member]
Notes Receivable And Residual Certificates
Long-Lived Tangible Asset [Axis]
Long-Lived Tangible Asset [Axis]
Borrower verification and servicing costs
Borrower verification and servicing costs
Borrower Verification And Servicing Costs
Borrower Verification And Servicing Costs
Other assets
Other Assets, Miscellaneous
Schedule of Key Terms for Capped Calls
Schedule Of Capped Calls [Table Text Block]
Schedule Of Capped Calls
Schedule of Collection Agency and Borrower Fees
Schedule Of Fees And Commissions [Table Text Block]
Schedule Of Fees And Commissions
Beneficial Interests [Abstract]
Beneficial Interests
Customer [Domain]
Customer [Domain]
Entity Central Index Key
Entity Central Index Key
PEO Name
PEO Name
Initial conversion price (in dollars per share)
Debt Instrument, Convertible, Conversion Price
Schedule of Maturities of All Borrowings
Schedule of Maturities of Long-Term Debt [Table Text Block]
Total revenue
Revenues
Trailing fee liabilities
Trailing Fee Liability, Measurement Input
Trailing Fee Liability, Measurement Input
Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year
Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member]
Principal payments received for notes receivable and repayments of residual certificates
Proceeds from Collection of Notes Receivable
Outstanding Aggregate Erroneous Compensation Amount
Outstanding Aggregate Erroneous Compensation Amount
Fair value, beginning balance
Fair value, ending balance
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value
Loans Held-for-Investment
Loans Held For Investment [Member]
Loans Held For Investment
10% market-servicing rates increase
Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Increase In Market-Servicing Rates
Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Increase In Market-Servicing Rates
Exercise Price
Award Exercise Price
Variable Interest Entity or Potential VIE, Information Unavailability, Disclosures [Abstract]
Variable Interest Entity or Potential VIE, Information Unavailability, Disclosures [Abstract]
Entity Filer Category
Entity Filer Category
Class of Stock [Domain]
Class of Stock [Domain]
Unrecognized stock-based compensation expense
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount
Customer operations
Customer operations, net of borrower verification and servicing costs
Customer Operations Expense
Customer Operations Expense
2028
Finite-Lived Intangible Asset, Expected Amortization, Year Three
Outstanding principal balance
Financing Receivable, before Allowance for Credit Loss
Gross Carrying Value
Finite-Lived Intangible Assets, Gross
Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year
Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member]
Entity Address, Address Line One
Entity Address, Address Line One
Entity Address, Address Line Two
Entity Address, Address Line Two
Engineering and product development
Engineering and product development
Research and Development Expense
Accrued expenses and other liabilities
Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities
Shares withheld related to net share settlement of restricted stock units (in shares)
Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation
Beneficial Interests
Beneficial Interest Disclosure [Text Block]
Beneficial Interest Disclosure
Fair Value as of Grant Date
Award Grant Date Fair Value
Stock options, RSUs, and ESPP (in shares)
Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements
RSUs granted (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period
Interest rate caps
Interest Rate Derivative Assets, at Fair Value
RSUs cancelled and forfeited (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period
Document Quarterly Report
Document Quarterly Report
Schedule of Significant Unobservable Inputs
Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]
Changed Peer Group, Footnote
Changed Peer Group, Footnote [Text Block]
Add: Dilutive effect of convertible senior notes, net
Dilutive Effect of Convertible Senior Notes, Net
Dilutive Effect of Convertible Senior Notes, Net
Change in fair value of other financial instruments
Increase (Decrease) in Other Financial Instruments Used in Operating Activities
Line of Credit Receivable
Line Of Credit Receivable [Member]
Line Of Credit Receivable
Counterparty Name [Domain]
Counterparty Name [Domain]
2027
Lessee, Operating Lease, Liability, to be Paid, Year Two
Adjustment To PEO Compensation, Footnote
Adjustment To PEO Compensation, Footnote [Text Block]
Options outstanding
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term
Title
Trading Arrangement, Individual Title
Peer Group Total Shareholder Return Amount
Peer Group Total Shareholder Return Amount
Changes in fair value recorded in earnings
Servicing Liability At Fair Value, Repayments And Other Changes At Fair Value, Gain (Loss) Included In Earnings
Servicing Liability At Fair Value, Repayments And Other Changes At Fair Value, Gain (Loss) Included In Earnings
Non-PEO NEO
Non-PEO NEO [Member]
Letter of credit outstanding
Letters of Credit Outstanding, Amount
Balances aggregate intrinsic value
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value
Beneficial interests obtained in connection with loan sale
Beneficial Interests Obtained In Connection With Loan Sale
Beneficial Interests Obtained In Connection With Loan Sale
Issuance of common stock under employee stock purchase plan
Stock Issued During Period, Value, Employee Stock Purchase Plan
Net gain (loss) on servicing rights and fair value adjustments
Gain (Loss) On Servicing Rights And Fair Value Adjustments
Gain (Loss) On Servicing Rights And Fair Value Adjustments
Sale of Stock [Axis]
Sale of Stock [Axis]
Net fair value and accrued interest adjustments
Financing Receivable, Allowance for Credit Loss
Award Type [Domain]
Award Type [Domain]
2029
Long-term and Short-term Debt, Maturity, Year Four
Long-term and Short-term Debt, Maturity, Year Four
2026
Lessee, Operating Lease, Liability, to be Paid, Year One
Equity Awards Adjustments
Equity Awards Adjustments [Member]
Leasehold improvements
Leasehold Improvements [Member]
Pension Benefits Adjustments, Footnote
Pension Benefits Adjustments, Footnote [Text Block]
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Line Items]
Compensation Amount
Outstanding Recovery Compensation Amount
Line of credit receivable
Line of credit receivable (at fair value)
Line Of Credit Receivable, Fair Value Disclosure
Line Of Credit Receivable, Fair Value Disclosure
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Dividend yield
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate
Recovery of Erroneously Awarded Compensation Disclosure [Line Items]
MNPI Disclosure Timed for Compensation Value
MNPI Disclosure Timed for Compensation Value [Flag]
Denominator:
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Shares available for issuance under employee stock purchase plan
Purchase rights committed under the ESPP
Employee Stock [Member]
Revenue:
Revenues [Abstract]
Restricted cash
Restricted Cash [Member]
Restricted Cash
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due [Line Items]
Sales and marketing
Sales and marketing, net of borrower acquisition costs
Selling and Marketing Expense
Purchases and originations of loans
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases
Aggregate Pension Adjustments Service Cost
Aggregate Pension Adjustments Service Cost [Member]
Payable to securitization note holders
Payables To Securitization Note Holders, Measurement Input
Payables To Securitization Note Holders, Measurement Input
Principal payments received for loans held-for-investment
Proceeds from Principal Repayment, Loan and Lease, Held-for-Investment
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets by Major Class [Axis]
Minimum
Minimum [Member]
Issuance of line of credit receivable
Issuance Of Line Of Credit Receivable
Issuance Of Line Of Credit Receivable
Company Selected Measure Name
Company Selected Measure Name
Borrowings
Debt Disclosure [Text Block]
Aggregate Available
Trading Arrangement, Securities Aggregate Available Amount
Beneficial interest liabilities (derivatives)
Beneficial Interest Liabilities [Member]
Beneficial Interest Liabilities
Cash paid for amounts included in the measurement of lease liabilities
Operating Lease, Payments
Capitalized cost amortization term
Capitalized Contract Cost, Amortization Period
Stock Appreciation Rights (SARs)
Stock Appreciation Rights (SARs) [Member]
Net income (loss) attributable to common stockholders, diluted
Net Income (Loss) Available to Common Stockholders, Diluted
Expected volatility, minimum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum
Upstart Small Dollar Loan Trust
Upstart Small Dollar Loan Trust [Member]
Upstart Small Dollar Loan Trust
Commitments and Contingencies
Commitments and Contingencies Disclosure [Text Block]
Weighted-average number of shares outstanding used in computing net income (loss) per share, diluted (in shares)
Weighted-average number of shares outstanding used in computing net income (loss) per share, diluted (in shares)
Weighted Average Number of Shares Outstanding, Diluted
Warehouse credit facilities
Warehouse Credit Facility [Member]
Warehouse Credit Facility
Fair value of options vested during period
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested in Period, Fair Value
Non-GAAP Measure Description
Non-GAAP Measure Description [Text Block]
Operating lease liability and right-of-use asset
Increase (Decrease) In Operating Lease Liability And Right of Use Asset
Increase (Decrease) In Operating Lease Liability And Right of Use Asset
Entity Small Business
Entity Small Business
Sales and marketing
Selling and Marketing Expense [Member]
Income Tax Disclosure [Abstract]
Document Transition Report
Document Transition Report
Settlements of beneficial interest liabilities
Payments On Beneficial Interest Liabilities
Payments On Beneficial Interest Liabilities
Underlying Securities
Award Underlying Securities Amount
Unpaid principal balance of loans
Variable Interest Entity, Primary Beneficiary, Maximum Loss Exposure, Amount
Equity Component [Domain]
Equity Component [Domain]
Document Period End Date
Document Period End Date
Income Taxes
Income Tax Disclosure [Text Block]
Common stock
Common Class A [Member]
Commitments to fund future advances
Contractual Obligation
Trailing fee liability (at fair value)
Trailing Fee Liability At Fair Value, Amount
Trailing Fee Liability At Fair Value, Amount
Schedule of Servicing Liabilities at Fair Value Rollforward
Schedule of Servicing Liabilities at Fair Value [Table Text Block]
Awards Close in Time to MNPI Disclosures, Table
Awards Close in Time to MNPI Disclosures [Table Text Block]
Options exercisable
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term
Borrower fees
Borrower Fees [Member]
Borrower Fees
Loan Servicing Liabilities
Loan Servicing Liabilities [Member]
Loan Servicing Liabilities
Document Type
Document Type
Fair Value, Inputs, Level 3
Fair Value, Inputs, Level 3 [Member]
Net Income (Loss) Per Share
Earnings Per Share [Text Block]
Name
Outstanding Recovery, Individual Name
Loss Contingencies [Table]
Loss Contingencies [Table]
Additional paid-in capital
Additional Paid in Capital
Product and Service [Axis]
Product and Service [Axis]
Variable lease payments
Variable Lease, Cost
Revenue from fees, net
Revenue from Contract with Customer, Excluding Assessed Tax
10% adverse change
Sensitivity Analysis of Fair Value, Assets, Impact of 10 Percent Adverse Change in Expected Prepayment Rates
Sensitivity Analysis of Fair Value, Assets, Impact of 10 Percent Adverse Change in Expected Prepayment Rates
Additions
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Additions
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Additions
Options vested and expected to vest (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number
Proceeds from sale of loans held-for-sale
Proceeds from Sale, Loan, Held-for-Sale
Payable to securitization note holders (at fair value)
Payable to securitization note holders
Payable To Securitization Note Holders, At Fair Value
Payable To Securitization Note Holders, At Fair Value
Statistical Measurement [Axis]
Statistical Measurement [Axis]
Options cancelled and forfeited (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price
Authorized share repurchase amount
Share Repurchase Program, Authorized, Amount
Unused commitment fee
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregate Erroneous Compensation Amount
Aggregate Erroneous Compensation Amount
Aggregate intrinsic value of options exercised
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value
Taxes paid related to net share settlement of equity awards
Payment, Tax Withholding, Share-Based Payment Arrangement
Unrealized loss on loans, loan charge-offs, and other fair value adjustments, net
Unrealized Gain (Loss), Charge-Offs, And Other Fair Value Adjustments, Net
Unrealized Gain (Loss), Charge-Offs, And Other Fair Value Adjustments, Net
Schedule of Other Assets
Schedule of Other Assets [Table Text Block]
Securities loaned, fair value of collateral
Outstanding borrowings
Securities Loaned, Fair Value of Collateral
Peer Group Issuers, Footnote
Peer Group Issuers, Footnote [Text Block]
Net income (loss) attributable to common stockholders, basic
Net Income (Loss) Available to Common Stockholders, Basic
Proceeds from beneficial interest assets (derivatives)
Proceeds From Beneficial Interest Assets, Operating Activities
Proceeds From Beneficial Interest Assets, Operating Activities
Weighted-Average Remaining Contractual Life (years)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Total operating expenses
Operating Expenses
Risk free rate, minimum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Other Assets [Abstract]
Net income (loss) per share, diluted (in dollars per share)
Earnings Per Share, Diluted
Supplemental disclosures of non-cash investing and financing activities
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans Held in Consolidated Securitization
Loans Held in Consolidated Securitization [Member]
Loans Held in Consolidated Securitization
Consolidation Items [Domain]
Consolidation Items [Domain]
Purchases and originations of loans held-for-investment
Payment for Acquisition, Loan, Held-for-Investment
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity, Not Primary Beneficiary [Member]
Sale of loans
Servicing Asset at Fair Value, Additions
Prepaid expenses
Prepaid Expense
Financing Receivable Portfolio Segment [Axis]
Financing Receivable Portfolio Segment [Axis]
Aggregate Intrinsic Value
Share Based Compensation Arrangement By Share Based Payment Award Options Aggregate Intrinsic Value [Abstract]
Share Based Compensation Arrangement By Share Based Payment Award Options Aggregate Intrinsic Value
Less: Present value adjustment
Lessee, Operating Lease, Liability, Undiscounted Excess Amount
Cash paid for income taxes, net
Income Taxes Paid, Net
2027
Finite-Lived Intangible Asset, Expected Amortization, Year Two
Accrued expenses
Accrued Liabilities
Auto Loans
Auto Loans [Member]
Auto Loans
Principal Amount
Long-Term Debt, Gross
Options granted (in dollars per share)
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price
Beneficial interests
Beneficial Interests, Net [Member]
Beneficial Interests, Net
Servicing Liability at Fair Value, Amount [Roll Forward]
Servicing Liability at Fair Value, Amount [Roll Forward]
Total undiscounted lease payments
Lessee, Operating Lease, Liability, to be Paid
Expiration Date
Trading Arrangement Expiration Date
Prepayment rate
Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Prepayment Speed
Credit risk rate
Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Expected Credit Losses
Property, equipment, and software, net
Total property, equipment, and software, net
Property, Plant and Equipment, Net
Reorganization expenses
Restructuring Charges
Trailing fee liabilities
Trailing Fee Liabilities, Fair Value Disclosure
Trailing Fee Liabilities, Fair Value Disclosure
Thereafter
Finite-Lived Intangible Asset, Expected Amortization, After Year Four
Finite-Lived Intangible Asset, Expected Amortization, After Year Four
Compensation Actually Paid vs. Net Income
Compensation Actually Paid vs. Net Income [Text Block]
Schedule of Restructuring and Related Costs [Table]
Restructuring Cost [Table]
Proceeds from issuance of common stock under employee stock purchase plan
Proceeds, Issuance of Shares, Share-Based Payment Arrangement, Excluding Option Exercised
Entity Current Reporting Status
Entity Current Reporting Status
Awards Close in Time to MNPI Disclosures
Awards Close in Time to MNPI Disclosures [Table]
Other consolidated VIEs
Other Variable Interest Entities [Member]
Other Variable Interest Entities
Proceeds from convertible notes issuance, net of debt issuance costs paid to lender
Issuance of 2032 Notes
Proceeds from Convertible Debt
Consolidated Entities [Domain]
Consolidated Entities [Domain]
Loans
Loans [Member]
Credit risk rate
Measurement Input, Entity Credit Risk [Member]
Statement of Financial Position [Abstract]
Executive Category:
Executive Category [Axis]
Change in fair value of servicing assets
Increase (Decrease) In Fair Value Of Servicing Assets
Increase (Decrease) In Fair Value Of Servicing Assets
Fiscal Year End Date
Current Fiscal Year End Date
Expected term (in years)
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term
Finite-Lived Intangible Assets, Major Class Name [Domain]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Weighted-Average Grant Date Fair Value Per Share
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted average grant date fair value (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value
Equity Awards Adjustments, Excluding Value Reported in Compensation Table
Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member]
Servicing Liabilities at Fair Value [Line Items]
Servicing Liabilities at Fair Value [Line Items]
Total (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
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]
Schedule of Aggregate Fair Value and Principal Outstanding of All Loans And Loans 90 Days or More Past Due
Financing Receivable, Past Due [Table Text Block]
Net income (loss) before income taxes
Income (Loss) Attributable to Parent, before Tax
Leases
Lessee, Operating Leases [Text Block]
Net cash provided by financing activities
Cash Provided by (Used in) Financing Activity, Including Discontinued Operation
Measure:
Measure [Axis]
Valuation Approach and Technique [Axis]
Valuation Approach and Technique [Axis]
Description of Business and Significant Accounting Policies
Basis of Presentation and Significant Accounting Policies [Text Block]
Long-Lived Tangible Asset [Domain]
Long-Lived Tangible Asset [Domain]
Stock repurchase program, remaining authorized repurchase amount (in dollars per share)
Share Repurchase Program, Remaining Authorized, Amount
Purchase of capped calls
Payments For Capped Calls
Payments For Capped Calls
2030
Long-term and Short-term Debt, Maturity, Year Five
Long-term and Short-term Debt, Maturity, Year Five
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Schedule of Servicing Liabilities at Fair Value [Table]
Servicing Liability at Fair Value, Activity [Table]
Pay vs Performance Disclosure, Table
Pay vs Performance [Table Text Block]
Forgone Recovery due to Violation of Home Country Law, Amount
Forgone Recovery due to Violation of Home Country Law, Amount
Risk-free interest rate
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate
Entity Tax Identification Number
Entity Tax Identification Number
Valuation Technique, Discounted Cash Flow
Valuation Technique, Discounted Cash Flow [Member]
Schedule of Fair Value Sensitivity of Loan Servicing Assets and Liabilities to Adverse Changes in Key Assumptions
Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block]
Schedule of Financial Assets and Liabilities from Variable Interest Entities
Schedule of Variable Interest Entities [Table Text Block]
Derivatives
Derivative [Member]
Number of VIEs whom exercised clean up calls
Variable Interest Entity, Qualitative Or Quantitative Information, Number Of Variable Interest Entity
Variable Interest Entity, Qualitative Or Quantitative Information, Number Of Variable Interest Entity
Options outstanding (in dollars per share)
Options outstanding (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price
Common stock, issued (in shares)
Common Stock, Shares, Issued
Weighted-average remaining lease term (in years)
Operating Lease, Weighted Average Remaining Lease Term
Goodwill and Intangible assets
Goodwill and Intangible Assets Disclosure [Text Block]
Convertible senior notes
Convertible Debt Securities [Member]
Trading Arrangement:
Trading Arrangement [Axis]
Total Shareholder Return Amount
Total Shareholder Return Amount
Loss Contingencies [Line Items]
Loss Contingencies [Line Items]
Changes in fair value recorded in earnings
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings
Security Exchange Name
Security Exchange Name
Issuance of line of credit receivable
Payments to Acquire Finance Receivables
Proceeds from sale of loans held-for-investment
Proceeds from Sale, Loan, Held-for-Investment
Capitalized internally developed software balances, net of accumulated amortization
Capitalized Computer Software, Net
Total borrowing capacity
Maximum borrowing capacity
Line of Credit Facility, Maximum Borrowing Capacity
Initial Strike Price per Share, Subject to Certain Adjustments (in dollars per share)
Debt Instrument, Convertible, Capped Calls Initial Strike Price
Debt Instrument, Convertible, Capped Calls Initial Strike Price
Operating expenses:
Operating Expenses [Abstract]
Cash held by institutional investor
Cash Held By Institutional Investor
Cash Held By Institutional Investor
Asset Class [Domain]
Asset Class [Domain]
Fair value adjustments and realized losses on beneficial interests, net
Charge-offs and changes in fair value recorded in earnings
Charge-offs and changes in fair value recorded in earnings
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings
Statement [Line Items]
Statement [Line Items]
Rule 10b5-1 Arrangement Adopted
Rule 10b5-1 Arrangement Adopted [Flag]
Cash and cash equivalents
Cash and cash equivalents
Cash and Cash Equivalent
Deposits
Deposits Assets
Fair Value Measurement Inputs and Valuation Techniques [Table]
Fair Value Measurement Inputs and Valuation Techniques [Table]
Line of Credit Receivable and Beneficial Interest Asset
Line Of Credit Receivable And Beneficial Interest Asset [Member]
Line Of Credit Receivable And Beneficial Interest Asset
Debt Activity [Roll Forward]
Convertible Debt Activity [Roll Forward]
Convertible Debt Activity
Risk free rate, maximum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum
Common Stock
Common Stock [Member]
RSUs vested (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period
Issuances
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances
Accrued payroll
Employee-related Liabilities
Change in cash, cash equivalents and restricted cash
Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation
Weighted-average effect of dilutive securities (in shares)
Weighted Average Number of Shares Outstanding, Diluted, Adjustment
Servicing Asset at Fair Value, Amount [Roll Forward]
Servicing Asset at Fair Value, Amount [Roll Forward]
Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Table]
Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Table]
Prepayment rate
Measurement Input, Prepayment Rate [Member]
2027
Long-term and Short-term Debt, Maturity, Year Two
Long-term and Short-term Debt, Maturity, Year Two
Statistical Measurement [Domain]
Statistical Measurement [Domain]
Customer D
Customer D [Member]
Customer D
Remaining 2025
Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year
Repayments of line of credit receivable
Proceeds from Collection of Finance Receivables
Asset Class [Axis]
Asset Class [Axis]
Valuation Approach and Technique [Domain]
Valuation Approach and Technique [Domain]
Leases [Abstract]
Consolidated warehouse entities
Consolidated Warehouse Entities [Member]
Consolidated Warehouse Entities
Subscription fee
Subscription Fee [Member]
Subscription Fee
Type of Restructuring [Domain]
Type of Restructuring [Domain]
Shares withheld related to net share settlement of restricted stock units
Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation
Trading Arrangements, by Individual
Trading Arrangements, by Individual [Table]
Net income (loss) per share, basic (in dollars per share)
Earnings Per Share, Basic
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table]
Liabilities
Liabilities, Fair Value Disclosure [Abstract]
Shares reserved of common stock for issuance (in shares)
Common Stock, Capital Shares Reserved for Future Issuance
Discount rate
Measurement Input, Discount Rate [Member]
Schedule of Segment Reporting Information, by Segment
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Conversion price maximum threshold
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger
Schedule of Beneficial Interests
Schedule Of Beneficial Interests [Table Text Block]
Schedule Of Beneficial Interests
Measurement Input Type [Domain]
Measurement Input Type [Domain]
Proceeds from beneficial interest assets (hybrid instruments)
Proceeds From Beneficial Interest Assets, Investing Activities
Proceeds From Beneficial Interest Assets, Investing Activities
Award Timing MNPI Disclosure
Award Timing MNPI Disclosure [Text Block]
Upstart Auto Warehouse Trust
UAWT Warehouse Credit Facility [Member]
UAWT Warehouse Credit Facility
Cash and cash equivalents
Cash and Cash Equivalents [Member]
Schedule of Servicing Assets at Fair Value Rollforward
Schedule of Servicing Assets at Fair Value [Table Text Block]
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity, Primary Beneficiary [Member]
Stock-based compensation expense
Share-Based Payment Arrangement, Expense
Accrued interest income
Financing Receivable, Accrued Interest, after Allowance for Credit Loss
Goodwill and Intangible Assets Disclosure [Abstract]
Cash payments made
Loss Contingency, Damages Paid, Value
Total liabilities and stockholders’ equity
Liabilities and Equity
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of Options
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Concentration Risk Benchmark [Axis]
Concentration Risk Benchmark [Axis]
Change in fair value of loans
Increase (Decrease) in Finance Receivables
Other changes
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Other Increase (Decrease)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Other Increase (Decrease)
Consecutive trading days
Debt Instrument, Convertible, Threshold Consecutive Trading Days
General, administrative, and other
General and Administrative Expense [Member]
2026 Notes
Twenty Twenty Six Notes [Member]
Twenty Twenty Six Notes
Accounting Policies [Abstract]
Immediate resale of loans
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Immediate Resale to Investors
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Immediate Resale to Investors
Schedule of Future Minimum Lease Payments
Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]
Concentration Risk Type [Domain]
Concentration Risk Type [Domain]
Pay vs Performance Disclosure [Line Items]
Operating lease liabilities
Operating lease liabilities
Operating Lease, Liability
Loans > 90 Days Past Due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Liabilities:
Liabilities
Liabilities [Abstract]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Loans on non-accrual status
Financing Receivable, Threshold Period Past Due
Schedule of Variable Interest Entities [Table]
Variable Interest Entity [Table]
2020 Equity Incentive Plan
2020 Equity Incentive Plan [Member]
2020 Equity Incentive Plan
Statement of Cash Flows [Abstract]
Company Selected Measure Amount
Company Selected Measure Amount
2028
Lessee, Operating Lease, Liability, to be Paid, Year Three
Gross debt issuance cost
Debt Issuance Costs, Gross
Measurement Input Type [Axis]
Measurement Input Type [Axis]
Name
Measure Name
Issuances
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances
Secured debt
Secured Debt [Member]
Schedule of Rollforward of Level 3 Liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]
Class of Stock [Line Items]
Class of Stock [Line Items]
Net Carrying Amount
Long-Term Debt
Total assets
Total assets
Assets
2026
Finite-Lived Intangible Asset, Expected Amortization, Year One
RSUs vested (in dollars 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
Servicing and other fees, net
Servicing Fees, Net [Member]
Servicing Fees, Net
Loan premium amortization
Amortization Of Loan Premium
Amortization Of Loan Premium
Cash flows from operating activities
Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract]
Receivable Type [Axis]
Receivable Type [Axis]
Expected credit loss rates on underlying loans
Expected Credit Loss Rate [Abstract]
Expected Credit Loss Rate
Concentration Risk Type [Axis]
Concentration Risk Type [Axis]
Cash and Restricted Cash
Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation [Abstract]
Assets
Assets, Fair Value Disclosure [Abstract]
2029
Finite-Lived Intangible Asset, Expected Amortization, Year Four
Variable Interest Entity [Line Items]
Variable Interest Entity [Line Items]
Variable Interest Entities and Consolidated Securitization
Consolidation, Variable Interest Entity, Policy [Policy Text Block]
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
Contract costs capitalized
Capitalized Contract Cost, Net
Engineering and product development
Engineering And Product Development [Member]
Engineering And Product Development
Fair Value, Inputs, Level 2
Fair Value, Inputs, Level 2 [Member]
Net cash proceeds
Proceeds from Accounts Receivable Securitization
Insider Trading Policies and Procedures Not Adopted
Insider Trading Policies and Procedures Not Adopted [Text Block]
Loans held in consolidated securitization
Securitized Loans, Measurement Input
Securitized Loans, Measurement Input
Plan Name [Axis]
Plan Name [Axis]
PEO
PEO [Member]
Employee Severance
Employee Severance [Member]
10% adverse change
Sensitivity Analysis of Fair Value, Liabilities, Impact of 10 Percent Adverse Change in Expected Credit Loss Rates
Sensitivity Analysis of Fair Value, Liabilities, Impact of 10 Percent Adverse Change in Expected Credit Loss Rates
Net changes in operating assets and liabilities:
Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract]
Expected volatility
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate
Accumulated Deficit
Retained Earnings [Member]
Amounts received from borrowers for previously charged-off loan
Proceeds, Financing Receivable, Previously Written off, Recovery
Schedule of Accrued Expenses and Other Liabilities
Schedule of Accrued Liabilities [Table Text Block]
Share-Based Payment Arrangement [Abstract]
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 Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation
Income Statement [Abstract]
Percentage of workforce reduction
Restructuring and Related Cost, Number of Positions Eliminated, Inception to Date Percent
Sale of Stock [Domain]
Sale of Stock [Domain]
20% adverse change
Sensitivity Analysis of Fair Value, Assets, Impact of 20 Percent Adverse Change in Expected Prepayment Rates
Sensitivity Analysis of Fair Value, Assets, Impact of 20 Percent Adverse Change in Expected Prepayment Rates
Intangible assets, net
Intangible Assets, Net (Excluding Goodwill)
Product and Service [Domain]
Product and Service [Domain]
Customer Concentration Risk
Customer Concentration Risk [Member]
Subscription agreements term
Subscription Agreements Term
Subscription Agreements Term
2030 Notes
Twenty Thirty Notes [Member]
Twenty Thirty Notes
Schedule Of Beneficial Interest [Table]
Schedule Of Beneficial Interest [Table]
Schedule Of Beneficial Interest
Restatement does not require Recovery
Restatement Does Not Require Recovery [Text Block]
Total liabilities
Liabilities, Fair Value Disclosure
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Obligation to Repurchase Loans
Obligation to Repurchase Receivables Sold [Member]
City Area Code
City Area Code
Award Timing, How MNPI Considered
Award Timing, How MNPI Considered [Text Block]
Repayments and settlements / Payments on beneficial interests
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements
Proceeds from borrowings
Proceeds from Long-Term Lines of Credit
Principal payments made on securitization notes
Repayments of Accounts Receivable Securitization
Cash flows from investing activities
Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract]
General, administrative, and other
General, administrative, and other
General and Administrative Expense
Pay vs Performance Disclosure
Pay vs Performance Disclosure [Table]
Securities retained under unconsolidated securitization transactions
Securities Retained Under Unconsolidated Securitization Transactions
Securities Retained Under Unconsolidated Securitization Transactions
Schedule of Stock Option Activity
Schedule of Stock Options Roll Forward [Table Text Block]
Schedule of Servicing Assets at Fair Value [Table]
Servicing Asset at Fair Value, Activity [Table]
Other liabilities
Other Liabilities
Goodwill
Goodwill
Maximum estimate of potential loss
Loss Contingency, Estimate of Possible Loss
Schedule of Operating Lease Expense and Supplemental Cash and Non-cash Information
Lease, Cost [Table Text Block]
Notes receivable and residual certificates
Notes Receivable, Fair Value Disclosure
20% adverse change
Sensitivity Analysis of Fair Value, Liabilities, Impact of 20 Percent Adverse Change in Expected Credit Loss Rates
Sensitivity Analysis of Fair Value, Liabilities, Impact of 20 Percent Adverse Change in Expected Credit Loss Rates
Supplemental disclosures of cash flow information
Supplemental Cash Flow Information [Abstract]
Restructuring Cost and Reserve [Line Items]
Restructuring Cost and Reserve [Line Items]
Other Performance Measure, Amount
Other Performance Measure, Amount
Weighted-Average Exercise Price Per Share
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Payment of debt issuance costs to third parties
Payments of Debt Issuance Costs
Discount rates
Discount Rate [Abstract]
Discount Rate
Loans receivable
Loans Receivable, Measurement Input
Loans Receivable, Measurement Input
Restricted cash
Restricted cash
Restricted Cash
Beneficial interest liabilities
Beneficial Interest, Liability, Measurement Input
Beneficial Interest, Liability, Measurement Input
Receivables
Accrued Fees and Other Revenue Receivable
Remaining 2025
Long-term and Short-term Debt, Maturity, Remainder Of Fiscal Year
Long-term and Short-term Debt, Maturity, Remainder Of Fiscal Year
Net cash used in investing activities
Cash Provided by (Used in) Investing Activity, Including Discontinued Operation
Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table
Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member]
Beneficial interest assets
Beneficial Interest, Asset, Measurement Input
Beneficial Interest, Asset, Measurement Input
Cash paid for interest
Interest Paid, Excluding Capitalized Interest, Operating Activity
Document Fiscal Year Focus
Document Fiscal Year Focus
Servicing Assets at Fair Value [Line Items]
Servicing Assets at Fair Value [Line Items]
Basis of Presentation
Basis of Accounting, Policy [Policy Text Block]
Operating lease right of use assets
Operating Lease, Right-of-Use Asset
Effective tax rate
Effective Income Tax Rate Reconciliation, Percent
Settlement of capped calls
Proceeds From Settlement Of Capped Calls
Proceeds From Settlement Of Capped Calls
Rent expense
Operating Lease, Cost
Capitalized software costs
Payments for Software
Conversion Period One
Conversion Period One [Member]
Conversion Period One
Plan Name [Domain]
Plan Name [Domain]
Period of recognition
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition
20% market-servicing rates increase
Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 20 Percent Increase In Market-Servicing Rates
Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 20 Percent Increase In Market-Servicing Rates
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
Change in fair value of beneficial interest assets
Increase (Decrease) In Fair Value Of Beneficial Interest Assets
Increase (Decrease) In Fair Value Of Beneficial Interest Assets
Loan purchase obligation
Purchase Obligation
Segment Information
Segment Reporting Disclosure [Text Block]
Schedule of Borrowings [Table]
Schedule Of Borrowings [Table]
Schedule of Borrowings [Table]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets [Line Items]
Customer E
Customer E [Member]
Customer E
Internally developed software impairment
Capitalized Computer Software, Impairments
Compensation Actually Paid vs. Total Shareholder Return
Compensation Actually Paid vs. Total Shareholder Return [Text Block]
Weighted Average
Weighted Average [Member]
Loans (at fair value)
Loans Receivable [Member]
Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table]
Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table]
Depreciation and amortization
Depreciation, Depletion and Amortization
Initial conversion rate (in shares)
Debt Instrument, Convertible, Conversion Ratio
Customer C
Customer C [Member]
Customer C
Convertible senior notes (in shares)
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities
Fair value, liability
Beneficial interest liabilities
Beneficial Interest Liabilities
Beneficial Interest Liabilities
Revolving Credit Facility
Revolving Credit Facility [Member]
Revenue from fees, net
Total revenue from fees, net
Revenue From Fees, Net
Revenue From Fees, Net
Arrangement Duration
Trading Arrangement Duration
Expected volatility, maximum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum
Computer and networking equipment
Computer Equipment [Member]
Segments [Axis]
Segments [Axis]
Fair Value by Liability Class [Domain]
Fair Value by Liability Class [Domain]
Local Phone Number
Local Phone Number
Additional 402(v) Disclosure
Additional 402(v) Disclosure [Text Block]
Stockholders’ Equity
Share-Based Payment Arrangement [Text Block]
Repurchase and retirement of common stock (in shares)
Stock Repurchased and Retired During Period, Shares
Assets
Assets
Assets [Abstract]
Credit Facility [Axis]
Credit Facility [Axis]
Underlying Security Market Price Change
Underlying Security Market Price Change, Percent
Debt Instrument [Axis]
Debt Instrument [Axis]
RSUs cancelled and forfeited (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value
Fair Value Measurement
Fair Value Disclosures [Text Block]
Gain on debt extinguishment
Gain on debt extinguishment
Gain (Loss) on Extinguishment of Debt
Credit Facility [Domain]
Credit Facility [Domain]
Stockholders’ equity:
Equity, Attributable to Parent [Abstract]
Other fees
Other Fees [Member]
Other Fees
Stated interest rate
Debt Instrument, Interest Rate, Stated Percentage
100 basis point increase
Sensitivity Analysis of Fair Value, Assets, Impact of 100 Basis Point Increase In Discount Rates
Sensitivity Analysis of Fair Value, Assets, Impact of 100 Basis Point Increase In Discount Rates
Loss contingency, ownership loan facilitated term
Loss Contingency, Ownership Loan Facilitated Term
Loss Contingency, Ownership Loan Facilitated Term
Loan servicing liabilities
Fair value, beginning balance
Fair value, ending balance
Loan servicing liabilities (at fair value)
Servicing Liability at Fair Value, Amount
Entity Registrant Name
Entity Registrant Name
Stock Price or TSR Estimation Method
Stock Price or TSR Estimation Method [Text Block]
Contribution Profit for Personal Lending
Contribution Profit: Personal Lending
Contribution Profit
Contribution Profit
Total assets
Assets, Fair Value Disclosure
Beneficial Interests
Beneficial Interests [Member]
Beneficial Interests
Non-marketable equity securities
Equity Securities without Readily Determinable Fair Value, Amount
Number of operating segments
Number of Operating Segments
Loan servicing assets
Fair value of loan servicing assets
Fair value, beginning balance
Fair value, ending balance
Loan servicing assets (at fair value)
Servicing Asset at Fair Value, Amount
Schedule of Aggregate Principal Outstanding of All Debt
Schedule of Debt [Table Text Block]
Payments for repurchases of convertible notes
Repurchases of 2026 Notes
Repayments of Convertible Debt
RSUs granted (in dollars 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
Schedule of Acquired Intangible Assets
Schedule of Finite-Lived Intangible Assets [Table Text Block]
Repayments of borrowings
Repayments of Long-Term Lines of Credit
Restatement Determination Date:
Restatement Determination Date [Axis]
Schedule of Sensitivity Analysis of Fair Value
Schedule of Sensitivity Analysis of Fair Value [Table Text Block]
Schedule of Sensitivity Analysis of Fair Value
Accounts Receivable
Accounts Receivable [Member]
2028
Long-term and Short-term Debt, Maturity, Year Three
Long-term and Short-term Debt, Maturity, Year Three
Interest expense
Interest Expense, Debt
Schedule of Rollforward of Level 3 Liabilities
Fair Value, Liabilities Measured on Recurring Basis [Table Text Block]
Name
Trading Arrangement, Individual Name
Fair value and other adjustments
Total fair value and other adjustments, net
Fair Value And Other Adjustments, Net
Fair Value And Other Adjustments, Net
Loans held-for-sale
Loan, Held-for-Sale, Fair Value Disclosure
Upstart High Yield Loan Trust
Upstart High Yield Loan Trust [Member]
Upstart High Yield Loan Trust
Aggregate principal amount
Debt Instrument, Face Amount
Name
Awards Close in Time to MNPI Disclosures, Individual Name
Repayments received
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Repayments Received
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Repayments Received
Beginning balance (in dollars per share)
Ending balance (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value
Restructuring Type [Axis]
Restructuring Type [Axis]
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Aggregate Erroneous Compensation Not Yet Determined
Aggregate Erroneous Compensation Not Yet Determined [Text Block]
Schedule of Customers Accounting for Greater Than 10% of Total Revenue
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]
Stock-based compensation expense
APIC, Share-Based Payment Arrangement, Increase for Cost Recognition
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Options vested and expected to vest
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value
Liability Class [Axis]
Liability Class [Axis]
Segments [Domain]
Segments [Domain]
Borrower acquisition costs
Borrower acquisition costs
Borrower Acquisition Costs
Borrower Acquisition Costs
Income Statement Location [Axis]
Statement of Income Location, Balance [Axis]
Fair Value Hierarchy and NAV [Domain]
Fair Value Hierarchy and NAV [Domain]
Accumulated depreciation and amortization
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment
Shares of Common Stock Covered, Subject to Anti-Dilution Adjustments (in shares)
Debt Instrument, Convertible, Capped Calls Number Of Shares Of Common Stock Covered
Debt Instrument, Convertible, Capped Calls Number Of Shares Of Common Stock Covered
Payable to Securitization Note Holders
Payables to Securitization Note Holders [Member]
Payables to Securitization Note Holders
Accrued interest
Interest Payable
Financial Asset, Period Past Due [Axis]
Financial Asset, Aging [Axis]
All Executive Categories
All Executive Categories [Member]
Repayments of line of credit receivable
Repayments of Line of Credit Receivable
Repayments of Line of Credit Receivable
Common stock, $0.0001 par value; 700,000,000 shares authorized; 93,469,721 and 97,275,544 shares issued and outstanding as of December 31, 2024 and September 30, 2025, respectively
Common Stock, Value, Issued
Schedule of Convertible Debt
Convertible Debt [Table Text Block]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table]
Kerry Whorton Cooper [Member]
Kerry Whorton Cooper
Commitments and Contingencies (Note 11)
Commitments and Contingencies
Purchase of loans for immediate resale
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchase Of Loans For Immediate Resale To Investors
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchase Of Loans For Immediate Resale To Investors
Additional repurchased amount
Debt Instrument, Additional Repurchased Face Amount
Debt Instrument, Additional Repurchased Face Amount
Settlement of borrowings in connection with loan sale
Notes Reduction
PEO Actually Paid Compensation Amount
PEO Actually Paid Compensation Amount
Options cancelled and forfeited (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period
Balance Sheet Components
Supplemental Balance Sheet Disclosures [Text Block]
Revenue from Contract with Customer [Abstract]
Fair Value
Debt Instrument, Fair Value Disclosure
Loans held in consolidated securitization
Loans Held In Consolidated Securitization, Fair Value Disclosure
Loans Held In Consolidated Securitization, Fair Value Disclosure
All Individuals
All Individuals [Member]
Long-term Debt, Type [Domain]
Long-Term Debt, Type [Domain]
Fair Value Disclosures [Abstract]
Purchases of property and equipment
Payments to Acquire Property, Plant, and Equipment
Name
Forgone Recovery, Individual Name
Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested
Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member]
Weighted average interest rate
Debt, Weighted Average Interest Rate
Cash, cash equivalents and restricted cash
Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract]
ESPP purchase price of common stock, percent of market price
Share-Based Compensation Arrangement by Share-Based Payment Award, Purchase Price of Common Stock, Percent
Debt Instrument Conversion [Domain]
Debt Instrument Conversion [Domain]
Debt Instrument Conversion [Domain]
ULT Warehouse Credit Facility - UnCommitted
ULT Warehouse Credit Facility - UnCommitted [Member]
ULT Warehouse Credit Facility - UnCommitted
Erroneous Compensation Analysis
Erroneous Compensation Analysis [Text Block]
Schedule of Finite-Lived Intangible Assets [Table]
Intangible Asset, Finite-Lived [Table]
Line of Credit Facility [Line Items]
Line of Credit Facility [Line Items]
Rule 10b5-1 Arrangement Terminated
Rule 10b5-1 Arrangement Terminated [Flag]
Upstart Loan Trust
ULT Warehouse Credit Facility [Member]
ULT Warehouse Credit Facility
Erroneously Awarded Compensation Recovery
Erroneously Awarded Compensation Recovery [Table]
Concentration Risk Benchmark [Domain]
Concentration Risk Benchmark [Domain]
Interest income
Interest income
Interest Income, Operating
Title of 12(b) Security
Title of 12(b) Security
Outstanding principal balance, asset
Beneficial Interest, Asset, Unpaid Principal Balance
Beneficial Interest, Asset, Unpaid Principal Balance
Accounts payable
Accounts Payable
Non-cash interest expense and other
Paid-in-Kind Interest
Earnings Per Share [Abstract]
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 Components of Interest Income and Fair Value Adjustments, Net
Interest Income and Interest Expense Disclosure [Table Text Block]
Segment, Reconciliation of Other Items from Segments to Consolidated [Table]
Segment, Reconciliation of Other Items from Segments to Consolidated [Table]
20% adverse change
Sensitivity Analysis of Fair Value, Assets, Impact of 20 Percent Adverse Change in Expected Credit Loss Rates
Sensitivity Analysis of Fair Value, Assets, Impact of 20 Percent Adverse Change in Expected Credit Loss Rates
Payable to investors
Payable To Investors
Payable To Investors
Dave Girouard [Member]
Dave Girouard
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Options exercised (in dollars per share)
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price
Award Timing Disclosures [Line Items]
Upstart Auto Warehouse Trust 2
UAWT Warehouse Credit Facility II [Member]
UAWT Warehouse Credit Facility II
Market-servicing rate
Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Market Servicing Rate
Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Market Servicing Rate
Beneficial interest liabilities (at fair value)
Beneficial Interest Liability
Net income (loss)
Net (loss) income
Net income (loss)
Net Income (Loss) Attributable to Parent
Schedule of Effective Tax Rates
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
Aggregate capital under risk-sharing arrangements
Beneficial Interests, Maximum Loss Exposure
Beneficial Interests, Maximum Loss Exposure
Award vesting period
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period
Adoption Date
Trading Arrangement Adoption Date
Financing Receivable, Past Due [Table]
Financing Receivable, Past Due [Table]
Customer [Axis]
Customer [Axis]
Customer relationships
Customer Relationships [Member]
Income (loss) from operations
Operating Income (Loss)
Accumulated deficit
Retained Earnings (Accumulated Deficit)
Loan Servicing Assets
Loan Servicing Assets [Member]
Loan Servicing Assets
Notes receivable and residual certificates
Notes Receivable, Measurement Input
Notes Receivable, Measurement Input
Expected credit risk rate spreads on underlying loans
Expected Credit Loss Rate (Liabilities) [Abstract]
Expected Credit Loss Rate (Liabilities)
Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested
Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member]
Class of Stock [Axis]
Class of Stock [Axis]
Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table
Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member]
Other income, net
Other Nonoperating Income (Expense)
Statement [Table]
Statement [Table]
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract]
Cash flows from financing activities
Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract]
Revenue Benchmark
Revenue Benchmark [Member]
Principal payments received for loans held-for-sale
Proceeds from Collection, Loan, Held-for-Sale
Sale of loans
Servicing Liability at Fair Value, Additions
Securitizations
Securitizations [Member]
Securitizations
Schedule of Rollforward of Level 3 Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]
Expected prepayment rates
Expected Prepayment Rates [Abstract]
Expected Prepayment Rates
All Adjustments to Compensation
All Adjustments to Compensation [Member]
Amendment Flag
Amendment Flag
Schedule of Fair Value by Classes of Loans Held by the Company
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block]
2029 Notes
Twenty Twenty Nine Notes [Member]
Twenty Twenty Nine Notes
Internally developed software
Software Development [Member]
Termination Date
Trading Arrangement Termination Date
Insider Trading Policies and Procedures Adopted
Insider Trading Policies and Procedures Adopted [Flag]
Receivable [Domain]
Receivable [Domain]
Weighted-average discount rate
Operating Lease, Weighted Average Discount Rate, Percent
Weighted-average number of shares outstanding used in computing net income (loss) per share, basic (in shares)
Weighted-average common shares outstanding used to calculate net income (loss) per share, basic (in shares)
Weighted Average Number of Shares Outstanding, Basic
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table]
Servicing fees
Servicing Fees [Member]
Servicing Fees
Gain on loan servicing rights, net
Gain (Loss) On Loan Servicing Rights And Sale Of Noncontrolling Interests, Net
Gain (Loss) On Loan Servicing Rights And Sale Of Noncontrolling Interests, Net
Schedule of Earnings Per Share, Basic and Diluted
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Options exercisable (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number
Subsequent Events [Abstract]
Segment Reporting [Abstract]
Debt Disclosure [Abstract]
Change in fair value of beneficial interest liabilities
Increase (Decrease) In Fair Value Of Beneficial Interest Liabilities
Increase (Decrease) In Fair Value Of Beneficial Interest Liabilities
Unamortized debt discount
Debt Instrument, Unamortized Discount
Outstanding principal balance, liability
Beneficial Interest, Liability, Unpaid Principal Balance
Beneficial Interest, Liability, Unpaid Principal Balance
Forgone Recovery due to Expense of Enforcement, Amount
Forgone Recovery due to Expense of Enforcement, Amount
Additions
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Additions
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Additions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock, par value (in dollars per share)
Common Stock, Par or Stated Value Per Share
Consolidated Entities [Axis]
Consolidated Entities [Axis]
Changes in fair value recorded in earnings
Servicing Asset At Fair Value, Repayments And Other Changes At Fair Value, Gain (Loss) Included In Earnings
Servicing Asset At Fair Value, Repayments And Other Changes At Fair Value, Gain (Loss) Included In Earnings
Options granted (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross
Settlements of beneficial interest assets (derivatives)
Payments On Beneficial Interest Assets, Operating Activities
Payments On Beneficial Interest Assets, Operating Activities
Use of Estimates
Use of Estimates, Policy [Policy Text Block]
Repayments and settlements
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements
Schedule of Employee Stock Purchase Plan Fair Value Assumptions
Schedule of Share-Based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]
Acquisition and settlements of beneficial interest assets (hybrid instruments)
Acquisition and Settlements of Beneficial Interest Assets
Acquisition and Settlements of Beneficial Interest Assets
Subsequent Events
Subsequent Events [Text Block]
Insider Trading Arrangements [Line Items]
Change in fair value of servicing liabilities
Increase (Decrease) In Fair Value Of Servicing Liabilities
Increase (Decrease) In Fair Value Of Servicing Liabilities
Total liabilities
Liabilities
Liabilities
Antidilutive Securities, Name [Domain]
Antidilutive Securities, Name [Domain]
Pension Adjustments Prior Service Cost
Pension Adjustments Prior Service Cost [Member]
Initial Cap Price per Share, Subject to Certain Adjustments (in dollars per share)
Debt Instrument, Convertible, Capped Calls Initial Cap Price
Debt Instrument, Convertible, Capped Calls Initial Cap Price
Repurchase amount
Debt Instrument, Repurchased Face Amount
Material Terms of Trading Arrangement
Material Terms of Trading Arrangement [Text Block]
Beneficial interest assets
Beneficial Interest, Asset, Fair Value
Beneficial Interest, Asset, Fair Value
Maximum value of shares to be sold
Sale Of Stock, Maximum Value Of Shares To Be Sold
Sale Of Stock, Maximum Value Of Shares To Be Sold
Consolidation Items [Axis]
Consolidation Items [Axis]
Counterparty Name [Axis]
Counterparty Name [Axis]
Trading days
Debt Instrument, Convertible, Threshold Trading Days
Entity Incorporation, State or Country Code
Entity Incorporation, State or Country Code
Non-NEOs
Non-NEOs [Member]