Premiums and Reinsurance Related Information - Premiums and Reinsurance, Allowance For Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Premium Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses, beginning of period	$ 42,130	$ 38,861	$ 42,006	$ 39,884
Cumulative effect adjustment resulting from changes in accounting principles	41,421	38,960	41,421	38,960
Change in expected credit losses	(709)	99	(585)	(924)
Allowance for expected credit losses, end of period	41,421	38,960	41,421	38,960
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward]
Allowance for expected credit losses, beginning of period	4,972	7,084	6,378	8,350
Cumulative effect adjustment resulting from changes in accounting principles	6,808	6,954	6,808	6,954
Reinsurance Recoverable, Credit Loss Expense (Reversal)	1,836	(130)	430	(1,396)
Allowance for expected credit losses, end of period	$ 6,808	$ 6,954	$ 6,808	$ 6,954

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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+ 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

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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