Premiums and Reinsurance Related Information - Premiums and Reinsurance, Allowance For Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Premium Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses, beginning of period	$ 38,960	$ 37,279	$ 39,884	$ 35,110
Cumulative effect adjustment resulting from changes in accounting principles	39,925	38,071	39,925	38,071
Change in expected credit losses	965	792	41	2,961
Allowance for expected credit losses, end of period	39,925	38,071	39,925	38,071
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses, beginning of period	6,954	10,255	8,350	8,404
Cumulative effect adjustment resulting from changes in accounting principles	6,599	8,332	6,599	8,332
Reinsurance Recoverable, Credit Loss Expense (Reversal)	(355)	(1,923)	(1,751)	(72)
Allowance for expected credit losses, end of period	$ 6,599	$ 8,332	$ 6,599	$ 8,332

Amount of expense (reversal of expense) for expected credit loss on premium receivable.

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- Definition

The carrying value as of the balance sheet date of the estimated valuation allowance to reduce gross premiums receivable to net realizable value.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Definition

Amount of expense (reversal of expense) for expected credit loss on reinsurance recoverable.

+ References

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- Definition

Amount of allowance for credit loss on reinsurance recoverable.

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