Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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

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The carrying amount as of the balance sheet date due the entity from (a) agents and insureds, (b) uncollected premiums and (c) others, net of the allowance for doubtful accounts.

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Amount, after valuation allowance, recoverable under reinsurance contracts including premium paid under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

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REINSURANCE - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
REINSURANCE - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024	Jun. 30, 2025	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Ceded Credit Risk [Line Items]
Premiums receivable (Note 5)	$ 8,130,508	$ 7,290,228
Premium receivable, allowance for credit loss	3,335	4,631	$ 3,272	$ 4,302	$ 4,546	$ 3,514
Reinsurance recoverable	4,100,000	4,500,000
Reinsurance recoverable, allowance for credit loss	$ 12,988	$ 11,730	$ 10,808	$ 13,176	$ 13,582	$ 13,280
Reinsurance Recoverable \| Reinsurer Concentration Risk \| Customer One
Ceded Credit Risk [Line Items]
Concentration risk, percentage	11.80%	12.60%
Reinsurance Recoverable \| Reinsurer Concentration Risk \| Customer Two
Ceded Credit Risk [Line Items]
Concentration risk, percentage	9.40%	11.00%
Reinsurance Recoverable \| Reinsurer Concentration Risk \| Customer Three
Ceded Credit Risk [Line Items]
Concentration risk, percentage	8.20%	8.30%
Allowance for Reinsurance Recoverable \| Customer Concentration Risk \| Customer One
Ceded Credit Risk [Line Items]
Concentration risk, percentage	19.20%	23.90%
Allowance for Reinsurance Recoverable \| Customer Concentration Risk \| Customer Two
Ceded Credit Risk [Line Items]
Concentration risk, percentage	17.60%	7.20%
Allowance for Reinsurance Recoverable \| Customer Concentration Risk \| Customer Three
Ceded Credit Risk [Line Items]
Concentration risk, percentage	4.60%	5.90%
Ceded Credit Risk, Secured \| Reinsurance Recoverable \| Reinsurer Concentration Risk
Ceded Credit Risk [Line Items]
Concentration risk, percentage	48.60%	55.70%
Ceded Credit Risk, Unsecured \| Reinsurance Recoverable \| Reinsurer Concentration Risk \| Standard & Poor's, A- Rating
Ceded Credit Risk [Line Items]
Concentration risk, percentage	50.10%	43.20%
Ceded Credit Risk, Unsecured \| Reinsurance Recoverable \| Reinsurer Concentration Risk \| Standard & Poor's, BBB Rating
Ceded Credit Risk [Line Items]
Concentration risk, percentage	1.30%	1.00%