Reinsurance - Schedule of Direct, Assumed, and Ceded Reinsurance Amounts (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Premiums written:
Direct	$ 1,335,475	$ 1,214,444	$ 4,051,124	$ 3,579,700
Assumed	7,611	9,087	20,009	20,058
Ceded	(185,446)	(165,206)	(530,771)	(456,758)
Net	1,157,640	1,058,325	3,540,362	3,143,000
Premiums earned:
Direct	1,279,783	1,123,444	3,727,847	3,229,170
Assumed	6,972	8,916	18,942	21,174
Ceded	(174,527)	(150,443)	(503,386)	(423,941)
Net	1,112,228	981,917	3,243,403	2,826,403
Loss and loss expense incurred:
Direct	1,194,224	741,288	2,957,610	2,053,511
Assumed	6,104	8,182	17,143	19,115
Ceded	(434,670)	(103,573)	(579,255)	(213,161)
Net	$ 765,658	$ 645,897	$ 2,395,498	$ 1,859,465

Amount of earned premiums assumed from other entities.

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