Losses and LAE - Mortgage Insurance Reserve for Losses and LAE Rollforward (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024
Loss reserve [Roll Forward]
Balance at beginning of period		$ 360,326
Deduct: Paid claims and LAE related to:
Balance at end of period		383,103
Mortgage Insurance revenues
Loss reserve [Roll Forward]
Balance at beginning of period		354,431	$ 364,923
Less: Reinsurance recoverables	[1]	34,144	25,074
Balance at beginning of period, net of reinsurance recoverables		320,287	339,849
Add: Losses and LAE incurred in respect of default notices reported and unreported in:
Current year	[1]	103,750	100,986
Prior years		(76,456)	(109,642)
Total incurred		27,294	(8,656)
Deduct: Paid claims and LAE related to:
Current year	[2]	220	91
Prior years		11,001	8,813
Total paid		11,221	8,904
Balance at end of period, net of reinsurance recoverables		336,360	322,289
Add: Reinsurance recoverables	[2]	40,872	28,918
Balance at end of period		$ 377,232	$ 351,207

[1] Related to ceded losses recoverable, if any, on reinsurance transactions. See Note 8 for additional information.

[2] Related to underlying defaulted loans with a most recent default notice dated in the year indicated. For example, if a loan had defaulted in a prior year, but then subsequently cured and later re-defaulted in the current year, that default would be considered a current year default.