Losses and LAE - Mortgage Insurance Reserve for Losses and LAE Rollforward (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Loss reserve [Roll Forward]
Balance at beginning of period	$ 370,148
Deduct: Paid claims and LAE related to:
Balance at end of period	357,470
Mortgage Insurance revenues
Loss reserve [Roll Forward]
Balance at beginning of period	364,923	$ 420,955
Less: Reinsurance recoverables	25,074	24,727
Balance at beginning of period, net of reinsurance recoverables	322,289	351,563	$ 339,849	$ 396,228
Add: Losses and LAE incurred in respect of default notices reported and unreported in:
Current year	100,986	87,594
Prior years	(109,642)	(126,081)
Total incurred	(8,656)	(38,487)
Deduct: Paid claims and LAE related to:
Current year	91	40
Prior years	8,813	6,138
Total paid	8,904	6,178
Balance at end of period, net of reinsurance recoverables	322,289	351,563
Add: Reinsurance recoverables	28,918	22,118
Balance at end of period	$ 351,207	$ 373,681