Fair Value Measurements - Sensitivity Analysis of Debt Securities Available-for-Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Sensitivity Analysis of Debt Securities Available-for-Sale [Line Items]
Total securities available for sale	$ 1,620,262	$ 345,702
Other asset-backed securities related to Structured Program transactions
Sensitivity Analysis of Debt Securities Available-for-Sale [Line Items]
Total securities available for sale	73,393
Discount rate
100 basis point increase	(927)
200 basis point increase	(1,836)
Annualized net charge-off rate
10% increase	(882)
20% increase	(1,771)
Annualized prepayment rate
10% increase	(203)
20% increase	$ (430)
Other asset-backed securities related to Structured Program transactions | Weighted- Average
Sensitivity Analysis of Debt Securities Available-for-Sale [Line Items]
Expected remaining weighted-average life (in years)	1 year 6 months