Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 28,231	$ 24,787
Administrative fee income, affiliate	0	100
Realized gains on contract derivative, net	1,909	2,267
Platform fees, net
Disaggregation of Revenue [Line Items]
Revenue	26,154	23,662
Administrative fee income, affiliate	0	100
Platform fees, net | Direct channel, home improvement loans
Disaggregation of Revenue [Line Items]
Revenue	500
Other revenues
Disaggregation of Revenue [Line Items]
Revenue	$ 2,077	$ 1,125