Losses and LAE - Schedule of Default to Claim Rates on Primary Portfolio (Details) - Mortgage insurance - Primary Mortgage Product	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
New defaults	7.50%	8.00%	8.00%
Foreclosure Stage Defaults	55.00%	65.00%	75.00%
Time in Default: less than 2 years
Defaults not in Foreclosure Stage	20.20%	21.00%	21.80%
Time in Default: less than 2 years | Maximum
Defaults not in Foreclosure Stage	42.70%	50.00%	55.00%
Time in Default: 2 - 5 years
Defaults not in Foreclosure Stage	45.00%	55.00%	65.00%
Time in Default: > 5 years
Defaults not in Foreclosure Stage	50.00%	60.00%	70.00%