Historical Loss and LAE Development - Reconciliation of Unpaid Losses and Settlement Expenses (LAE) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Unpaid losses and LAE at beginning of year
Gross	$ 2,886,819	$ 2,693,470
Ceded	(746,798)	(755,425)
Net	2,140,021	1,938,045
Increase (decrease) in incurred losses and LAE
Current accident year	228,708	208,243
Prior accident year	(35,464)	(31,005)
Total incurred	193,244	177,238
Loss and LAE payments for claims incurred
Current accident year	(10,045)	(9,827)
Prior accident years	(135,794)	(115,040)
Total paid	(145,839)	(124,867)
Net unpaid losses and LAE at end of year	2,187,426	1,990,416
Unpaid losses and LAE at end of year
Gross	2,927,929	2,743,245
Ceded	(740,503)	(752,829)
Net unpaid losses and LAE at end of year	$ 2,187,426	$ 1,990,416