RESERVE FOR LOSSES AND LOSS EXPENSES - Narrative (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Net loss and loss expenses	$ 1,467,256	$ 1,515,182
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	$ 70,000	$ 127,000