Borrowings - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Borrowings [Line Items]
Total payments due	$ 782,801	$ 709,787
Unamortized debt discount	(13,579)	(14,355)
Total borrowings	769,222	695,432
Warehouse credit facilities | Revolving Credit Facility
Schedule of Borrowings [Line Items]
Total payments due	121,551	48,030
Risk retention funding loan
Schedule of Borrowings [Line Items]
Total payments due	0	507
Convertible senior notes
Schedule of Borrowings [Line Items]
Total payments due	$ 661,250	$ 661,250