General - Effects of Reinsurance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Premiums Earned
Ceded	$ (63,200)	$ (42,400)	$ (224,300)	$ (104,900)
Net	1,410,400	1,320,652	4,060,208	3,723,355
Reinsurance Contract [Axis]: Property Quota Share Reinsurance Contract ("Quota Share")
Premiums Written
Assumed			11,000
Property & Casualty
Premiums Written
Direct	1,554,908	1,458,934	4,470,544	4,133,920
Ceded	(63,467)	(42,938)	(224,202)	(106,121)
Assumed	589	137	26,084	15,381
Net	1,492,030	1,416,133	4,272,426	4,043,180
Premiums Earned
Direct	1,459,263	1,351,870	4,242,795	3,794,663
Ceded	(63,243)	(42,444)	(224,342)	(104,894)
Assumed	6,941	3,856	19,608	11,578
Net	$ 1,402,961	$ 1,313,282	$ 4,038,061	$ 3,701,347