Loss Reserves (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 loan	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan	Dec. 31, 2019 USD ($)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years | $			$ 17,317	$ (47,760)
Prior years | $			$ 93,937	$ 165,844
Percentage of prior year default inventory resolved			61.00%	61.00%
Premium refund liability, expected claim payments | $	$ 29,000		$ 29,000		$ 30,000
Primary Delinquent Inventory [Roll Forward]
Delinquent inventory at the beginning of period (in loans) | loan	69,326	29,795	30,028	32,898
New notices (in loans) | loan	20,924	14,019	90,906	40,545
Cures (in loans) | loan	(25,446)	(12,592)	(54,523)	(39,822)
Paids (including those charged to a deductible or captive) (in loans) | loan	(375)	(1,045)	(1,933)	(3,345)
Rescissions and denials (in loans) | loan	(11)	(42)	(60)	(141)
Other items removed from inventory (in loans) | loan	0	(195)	0	(195)
Delinquent inventory at end of period (in loans) | loan	64,418	29,940	64,418	29,940
Probable loss on litigation claims paying practices
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years | $				$ 23,500
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 | $			$ (1,626)	(94,294)
Increase in estimated severity on primary defaults
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years | $			13,503	2,637
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 | $			$ 5,440	$ 43,897