Fair Value Measurement - Loans at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Fair value	$ 623,763	$ 252,477
Loans (at fair value)
Financing Receivable, Past Due [Line Items]
Outstanding principal balance	689,424	277,228
Net fair value and accrued interest adjustments	(65,661)	(24,751)
Fair value	623,763	252,477
Loans (at fair value) | Auto Loans
Financing Receivable, Past Due [Line Items]
Fair value	382,500	50,100
Loans > 90 Days Past Due | Loans (at fair value)
Financing Receivable, Past Due [Line Items]
Outstanding principal balance	4,134	1,979
Net fair value and accrued interest adjustments	(3,414)	(1,692)
Fair value	$ 720	$ 287