Losses and LAE - Reserve for Losses and LAE by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	$ 374,945	$ 360,326
Mortgage insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	369,090	354,431	$ 356,673	$ 364,923
Title insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	5,855	5,895
Primary case | Mortgage insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	347,996	336,553
Primary IBNR and LAE | Mortgage insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	13,827	13,399
Pool and other | Mortgage insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	$ 7,267	$ 4,479