Premiums and Reinsurance Related Information - Premiums and Reinsurance, Allowance For Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Premium Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses, beginning of period	$ 38,861	$ 35,039	$ 39,884	$ 35,110
Cumulative effect adjustment resulting from changes in accounting principles	38,960	37,279	38,960	37,279
Change in expected credit losses	99	2,240	(924)	2,169
Allowance for expected credit losses, end of period	38,960	37,279	38,960	37,279
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses, beginning of period	7,084	9,185	8,350	8,404
Cumulative effect adjustment resulting from changes in accounting principles	6,954	10,255	6,954	10,255
Reinsurance Recoverable, Credit Loss Expense (Reversal)	(130)	1,070	(1,396)	1,851
Allowance for expected credit losses, end of period	$ 6,954	$ 10,255	$ 6,954	$ 10,255