Losses and LAE - Mortgage Insurance Reserve for Losses and LAE Rollforward (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
Loss reserve [Roll Forward]
Balance at beginning of period		$ 360,326
Deduct: Paid claims and LAE related to:
Balance at end of period		374,945
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]	53,740	53,688
Prior years		(38,400)	(60,574)
Total incurred		15,340	(6,886)
Deduct: Paid claims and LAE related to:
Current year	[2]	0	0
Prior years		4,233	3,387
Total paid		4,233	3,387
Balance at end of period, net of reinsurance recoverables		331,394	329,576
Add: Reinsurance recoverables	[2]	37,696	27,097
Balance at end of period		$ 369,090	$ 356,673

[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.