RESERVE FOR LOSSES AND LOSS EXPENSES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Net loss and loss expenses	$ 724,680	$ 741,655
Catastrophe and Weather-related Events
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Net loss and loss expenses	$ 38,000	$ 60,000

Amount, after effects of reinsurance, of expense for claims incurred in the current reporting period and related claims settlement costs.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration