Loss Reserves - Delinquent Items (Details) - loan	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Aging of the Primary Delinquent Inventory [Abstract]
3 months or less (in loans)	6,513		11,542	50,646
3 months or less (as a percent)	15.00%		20.00%	73.00%
4 - 11 months (in loans)	12,840		34,620	8,370
4 - 11 months (as a percent)	30.00%		60.00%	12.00%
12 months or more (in loans)	23,646		11,548	10,310
12 months or more (as a percent)	55.00%		20.00%	15.00%
Total primary delinquent inventory (in loans)	42,999	52,775	57,710	69,326	27,384	30,028
Total primary delinquent inventory (as a percent)	100.00%		100.00%	100.00%
Primary claims received inventory included in ending delinquent inventory (in loans)	159		159	247
Percent of 12 months or more delinquent inventory, delinquent for more than 36 months (as a percent)	15.00%		31.00%	33.00%