Loss Reserves (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($) loan	Jun. 30, 2022 loan	Jun. 30, 2023 USD ($) loan	Jun. 30, 2022 USD ($) loan	Dec. 31, 2022 USD ($)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Increase (decrease) in loss reserves			$ (27,307)	$ (156,344)
Losses incurred related to prior year notices			(100,710)	$ (186,582)
Premium refund liability, expected claim payments	$ 23,200		$ 23,200		$ 25,500
Primary Delinquent Inventory [Roll Forward]
Delinquent inventory at the beginning of period (in loans) | loan	24,757	30,462	26,387	33,290
New notices (in loans) | loan	10,580	9,396	21,877	20,099
Cures (in loans) | loan	(11,156)	(12,677)	(23,763)	(25,877)
Paid claims (in loans) | loan	(348)	(319)	(659)	(641)
Rescissions and denials (in loans) | loan	(10)	(7)	(19)	(16)
Delinquent inventory at end of period (in loans) | loan	23,823	26,855	23,823	26,855
$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			$ 9,000
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]
Losses incurred related to prior year notices			(99,148)	$ (186,163)
Change in estimates related to severity on primary defaults, pool reserves, LAE reserves, reinsurance, and other
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Losses incurred related to prior year notices			$ (1,562)	$ (419)