Marketplace Revenue - Components of Marketplace Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Gain on sales of loans	$ 13,221	$ 29,319	$ 27,346	$ 53,429
Net fair value adjustments	(23,442)	9,647	(38,856)	24,896
Total marketplace revenue	82,783	206,384	178,417	386,350
Origination fees
Disaggregation of Revenue [Line Items]
Revenue	70,989	149,252	141,532	271,345
Servicing fees
Disaggregation of Revenue [Line Items]
Revenue	$ 22,015	$ 18,166	$ 48,395	$ 36,680