Premiums and Reinsurance Related Information - Premiums and Reinsurance, Allowance For Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Premium Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses, beginning of period	$ 39,884	$ 35,110
Cumulative effect adjustment resulting from changes in accounting principles	38,861	35,039
Change in expected credit losses	(1,023)	(71)
Allowance for expected credit losses, end of period	38,861	35,039
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses, beginning of period	8,350	8,404
Cumulative effect adjustment resulting from changes in accounting principles	7,084	9,185
Reinsurance Recoverable, Credit Loss Expense (Reversal)	(1,266)	781
Allowance for expected credit losses, end of period	$ 7,084	$ 9,185