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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Amount of allowance for credit loss on reinsurance recoverable.

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REINSURANCE - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
REINSURANCE - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Jun. 30, 2023	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Ceded Credit Risk [Line Items]
Premiums receivable	$ 5,928,809	$ 5,139,471
Premium receivable, allowance for credit loss	3,232	4,606	$ 3,151	$ 4,769	$ 4,350	$ 2,776
Reinsurance recoverable	4,300,000	4,700,000
Reinsurance recoverable, allowance for credit loss	$ 10,296	$ 12,169	$ 11,456	$ 12,087	$ 9,005	$ 8,344
Reinsurer Concentration Risk \| Reinsurance Recoverable \| Customer One
Ceded Credit Risk [Line Items]
Concentration risk, percentage	18.40%	20.80%
Reinsurer Concentration Risk \| Reinsurance Recoverable \| Customer Two
Ceded Credit Risk [Line Items]
Concentration risk, percentage	10.50%	7.00%
Reinsurer Concentration Risk \| Reinsurance Recoverable \| Customer Three
Ceded Credit Risk [Line Items]
Concentration risk, percentage	7.20%	5.40%
Customer Concentration Risk \| Allowance for Reinsurance Recoverable \| Customer One
Ceded Credit Risk [Line Items]
Concentration risk, percentage	11.90%	14.30%
Customer Concentration Risk \| Allowance for Reinsurance Recoverable \| Customer Two
Ceded Credit Risk [Line Items]
Concentration risk, percentage	6.90%	9.10%
Customer Concentration Risk \| Allowance for Reinsurance Recoverable \| Customer Three
Ceded Credit Risk [Line Items]
Concentration risk, percentage	5.50%	8.00%
Ceded Credit Risk, Secured \| Reinsurer Concentration Risk \| Reinsurance Recoverable
Ceded Credit Risk [Line Items]
Concentration risk, percentage	51.90%	47.20%
Ceded Credit Risk, Unsecured \| Reinsurer Concentration Risk \| Reinsurance Recoverable \| Standard & Poor's, A- Rating
Ceded Credit Risk [Line Items]
Concentration risk, percentage	47.40%	52.00%
Ceded Credit Risk, Unsecured \| Reinsurer Concentration Risk \| Reinsurance Recoverable \| Standard & Poor's, BBB Rating
Ceded Credit Risk [Line Items]
Concentration risk, percentage	0.70%	0.80%