Financial Instruments and Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets			$ 0
Total financial liabilities			0
Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	$ 453,529,000	$ 751,781,000
Total financial liabilities	204,627,000
Fair Value, Recurring | Securitization Debt of Consolidated VIEs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities	204,627,000
Fair Value, Recurring | Finance Receivables
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	189,469,000
Fair Value, Recurring | Finance Receivables at Fair Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	35,954,000
Fair Value, Recurring | Beneficial Interests in Securitizations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	15,603,000
Fair Value, Recurring | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents	189,504,000	601,807,000
Fair Value, Recurring | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents	22,999,000	149,974,000
Fair Value, Recurring | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	189,504,000	601,807,000
Fair Value, Recurring | Level 1 | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents	189,504,000	601,807,000
Fair Value, Recurring | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	38,602,000	149,974,000
Total financial liabilities	204,627,000
Fair Value, Recurring | Level 2 | Securitization Debt of Consolidated VIEs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities	204,627,000
Fair Value, Recurring | Level 2 | Beneficial Interests in Securitizations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	15,603,000
Fair Value, Recurring | Level 2 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents	22,999,000	$ 149,974,000
Fair Value, Recurring | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	225,423,000		0
Total financial liabilities			$ 0
Fair Value, Recurring | Level 3 | Finance Receivables
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	189,469,000
Fair Value, Recurring | Level 3 | Finance Receivables at Fair Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial assets	$ 35,954,000