Loss Reserves (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) loan	Sep. 30, 2021 loan	Sep. 30, 2022 USD ($) loan	Sep. 30, 2021 USD ($) loan	Dec. 31, 2021 USD ($)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Increase (decrease) in loss reserves			$ (280,152)	$ 52,372
Current year increase in reserves			104,086	95,534
Prior years decrease in reserves			(327,512)	$ (5,968)
Premium refund liability, expected claim payments	$ 28,100		$ 28,100		$ 37,300
Primary Delinquent Inventory [Roll Forward]
Delinquent inventory at the beginning of period (in loans) | loan	26,855	42,999	33,290	57,710
New notices (in loans) | loan	10,990	9,862	31,089	31,909
Cures (in loans) | loan	(11,494)	(14,813)	(37,371)	(50,901)
Paid claims (in loans) | loan	(337)	(298)	(978)	(956)
Rescissions and denials (in loans) | loan	(11)	(11)	(27)	(23)
Other items removed from inventory (in loans) | loan	(125)	(360)	(125)	(360)
Delinquent inventory at end of period (in loans) | loan	25,878	37,379	25,878	37,379
$1,000 Increase/Decrease In Average Severity Reserve Factor
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Increase (decrease) in loss reserves			$ 11,000
One Percentage Point Increase/Decrease In Average Claim Rate Reserve Factor
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Increase (decrease) in loss reserves			15,000
Increase (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 decrease in reserves			(324,556)	$ (18,147)
Increase (decrease) in estimated severity on primary defaults
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years decrease in reserves			(18,682)	(105)
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 decrease in reserves			$ 15,726	12,284
Change in estimates related to IBNR reserves
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Current year increase in reserves				5,900
Probable Loss On Litigation Claims Paying Practices
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior years decrease in reserves				$ 6,300