Losses and LAE - Reserve for Losses and LAE by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	$ 361,833	$ 370,148
Mortgage insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	356,673	364,923	$ 399,850	$ 420,955
Title insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	5,160	5,225
Primary case | Mortgage insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	336,929	344,235
Primary IBNR and LAE | Mortgage insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	11,956	12,177
Pool and other | Mortgage insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Total reserve for losses and LAE	$ 7,788	$ 8,511