Historical Loss and LAE Development - Reconciliation of Unpaid Losses and Settlement Expenses (LAE) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Unpaid losses and LAE at beginning of year
Gross	$ 2,693,470	$ 2,446,025
Ceded	(755,425)	(757,349)
Net	1,938,045	1,688,676
Increase (decrease) in incurred losses and LAE
Current accident year	208,243	186,217
Prior accident year	(31,005)	(42,393)
Total incurred	177,238	143,824
Loss and LAE payments for claims incurred
Current accident year	(9,827)	(12,975)
Prior accident years	(115,040)	(102,011)
Total paid	(124,867)	(114,986)
Net unpaid losses and LAE at end of year	1,990,416	1,717,514
Unpaid losses and LAE at end of year
Gross	2,743,245	2,532,190
Ceded	(752,829)	(814,676)
Net unpaid losses and LAE at end of year	$ 1,990,416	$ 1,717,514