Loss Reserves (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) loan	Mar. 31, 2019 USD ($) loan	Dec. 31, 2019 USD ($)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years	$ 1,157	$ (8,425)
Prior years	$ 45,633	$ 56,365
Decrease in delinquency notices, percent	9.00%
Increase in IBNR reserves	$ 7,800
Premium refund liability, expected claim payments	$ 29,000		$ 30,000
Primary Delinquent Inventory [Roll Forward]
Delinquent inventory at the beginning of period (in loans) | loan	30,028	32,898
New notices (in loans) | loan	12,398	13,611
Cures (in loans) | loan	(14,113)	(14,348)
Paids (including those charged to a deductible or captive) (in loans) | loan	(897)	(1,188)
Rescissions and denials (in loans) | loan	(32)	(52)
Delinquent inventory at end of period (in loans) | loan	27,384	30,921
Decrease in estimated claim rate on primary defaults
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years	$ 0	$ (31,000)
Increase in estimated severity on primary defaults
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years	3,000	0
Change in estimates related to pool reserves, LAE reserves, reinsurance, and other
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years	$ (2,000)	$ 23,000