Financial Instruments and Fair Value Measurements - Summary of Fair Value of Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securitization Debt, Carrying value	$ 729,372	$ 626,583	$ 449,393
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible Senior Notes, Carrying value	287,926	286,800
Convertible Senior Notes, Fair value	145,244	$ 152,506
Level 2 | Securitization Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securitization Debt, Carrying value	242,295
Securitization Debt, Fair Value	$ 248,526