Losses and LAE - Additional Information (Details)	12 Months Ended
	Dec. 31, 2024 Default Payment	Dec. 31, 2023 Default	Dec. 31, 2022 Default
Number of payments missed for insured loans | Payment	2
Mortgage Insurance revenues | TEXAS | Primary Risk In Force | Geographic Concentration Risk
Concentration risk, percentage	10.00%	10.00%
Mortgage Insurance revenues | TEXAS | New Insurance Written | Geographic Concentration Risk
Concentration risk, percentage	11.00%	13.00%	12.00%
Primary Mortgage Product | Mortgage Insurance revenues
New primary defaults | Default	50,535	44,007	37,738
Default to claim rate estimate, gross, for new defaults	7.50%	8.00%	8.00%
Claim Severity rate of defaulted risk exposure	89.00%	98.00%