Loss Reserves - Reconciliation of Beginning and Ending Balances (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Loss Reserve [Roll Forward]
Reserve at beginning of period	$ 674,019	$ 985,635
Less reinsurance recoverable	33,328	48,474
Net reserve at beginning of period	640,691	937,161
Losses and LAE incurred in respect of delinquency notices received in:
Current year	142,644	155,808
Prior years	(47,760)	(146,931)
Total losses incurred	94,884	8,877
Losses and LAE paid in respect of delinquency notices received in:
Current year	980	2,449
Prior years	165,844	257,808
Reinsurance terminations	(13,980)	(1,984)
Total losses paid	152,844	258,273
Net reserve at end of period	582,731	687,765
Plus reinsurance recoverables	19,566	33,281
Reserve at end of period	$ 602,297	$ 721,046