Loss Reserves - Delinquent Items (Details) - loan	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Insurance Loss Reserves [Abstract]
Percent of delinquency inventory subject to a Covid-19 forbearance plan (as a percent)	67.00%
Aging of the Primary Delinquent Inventory [Abstract]
3 months or less (in loans)	50,646		9,447	8,970
3 months or less (as a percent)	73.00%		32.00%	30.00%
4 - 11 months (in loans)	8,370		9,664	8,951
4 - 11 months (as a percent)	12.00%		32.00%	30.00%
12 months or more (in loans)	10,310		10,917	11,874
12 months or more (as a percent)	15.00%		36.00%	40.00%
Total primary delinquent inventory (in loans)	69,326	27,384	30,028	29,795	30,921	32,898
Total primary delinquent inventory (as a percent)	100.00%		100.00%	100.00%
Primary claims received inventory included in ending delinquent inventory (in loans)	247		538	630
Percent of 12 months or more delinquent inventory, delinquent for more than 36 months (as a percent)	33.00%		36.00%	37.00%