Reinsurance - Schedule of Direct, Assumed, and Ceded Reinsurance Amounts (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Premiums written:
Direct	$ 5,319,457	$ 4,725,459	$ 4,068,518
Assumed	27,557	23,999	32,320
Ceded	(717,013)	(614,926)	(527,248)
Net	4,630,001	4,134,532	3,573,590
Premiums earned:
Direct	5,034,952	4,386,556	3,880,522
Assumed	26,450	25,027	30,742
Ceded	(684,955)	(583,977)	(537,884)
Net	4,376,447	3,827,606	3,373,380
Loss and loss expense incurred:
Direct	3,909,463	2,738,301	2,537,638
Assumed	21,540	19,581	23,160
Ceded	(766,519)	(273,597)	(449,020)
Net	$ 3,164,484	$ 2,484,285	$ 2,111,778

Amount of earned premiums assumed from other entities.

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