Losses and LAE - Net Outstanding Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Total gross reserve for losses and LAE	$ 360,326	$ 370,148
Mortgage insurance
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Reserve for losses and LAE, net of reinsurance	308,290
Reinsurance recoverable on unpaid claims	34,144	25,074	$ 24,727	$ 66,676
Unallocated LAE	11,997
Total gross reserve for losses and LAE	354,431	$ 364,923	$ 420,955	$ 823,136
Mortgage insurance | Mortgage insurance
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Reserve for losses and LAE, net of reinsurance	$ 308,290