Securitizations and Variable Interest Entities - Narrative (Details) $ in Thousands	1 Months Ended
	Aug. 31, 2018 securitizationTransaction	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Variable Interest Entity [Line Items]
Restricted cash		$ 204,633	$ 60,514
Number Of Securitization Transactions | securitizationTransaction	3
Notes receivable and residual certificates (at fair value)
Variable Interest Entity [Line Items]
Loans, notes receivables, and residual certificates		8,288	19,074
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, notes receivables, and residual certificates		$ 8,300	$ 18,900