Fair Value Measurement - Loans at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Fair value	$ 700,455	$ 252,477
Loans (at fair value)
Financing Receivable, Past Due [Line Items]
Outstanding principal balance	785,856	277,228
Net fair value and accrued interest adjustments	(85,401)	(24,751)
Fair value	700,455	252,477
Loans (at fair value) | Auto Loans
Financing Receivable, Past Due [Line Items]
Fair value	394,100	50,100
Loans > 90 Days Past Due | Loans (at fair value)
Financing Receivable, Past Due [Line Items]
Outstanding principal balance	8,801	1,979
Net fair value and accrued interest adjustments	(7,056)	(1,692)
Fair value	$ 1,745	$ 287