Variable Interest Entities - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Loans (at fair value)	$ 597,981	$ 252,477
Restricted cash	254,866	204,633
Notes receivable and residual certificates (at fair value)
Variable Interest Entity [Line Items]
Loans (at fair value)	6,384	8,288
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Restricted cash	7,200	7,200
Variable Interest Entity, Not Primary Beneficiary | Notes receivable and residual certificates (at fair value)
Variable Interest Entity [Line Items]
Loans (at fair value)	$ 6,400	$ 8,300