Liability for Losses Under Representations and Warranties (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
During the year:
Balance at beginning of period	$ 32,688	$ 21,446
Provision for losses on loans sold resulting from sales of loans	10,053	3,712
Provision for losses on loans sold reduction in liability due to change in estimate	(3,685)	(1,676)
Losses incurred, net	(628)	(280)
Balance at end of period	38,428	23,202
Unpaid principal balance of loans subject to representations and warranties at end of period	$ 220,865,034	$ 186,517,598