DERIVATIVE INSTRUMENTS - Summary of Total Unrealized and Realized Gains (Loss) on Derivatives Not Designated as Hedges Recorded in Earnings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]
Unrealized and realized gains (loss) recognized in earnings for derivatives not designated as hedges	$ 7,656	$ 4,346	$ (2,434)
Not Designated as Hedging Instruments
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]
Unrealized and realized gains (loss) recognized in earnings for derivatives not designated as hedges	(20,411)	(43,650)	32,697
Not Designated as Hedging Instruments | Investment Portfolio | Foreign exchange forward contracts | Net investment gains (losses)
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]
Unrealized and realized gains (loss) recognized in earnings for derivatives not designated as hedges	7,656	4,346	(2,434)
Not Designated as Hedging Instruments | Relating to underwriting portfolio: | Foreign exchange forward contracts | Foreign exchange (losses) gains
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]
Unrealized and realized gains (loss) recognized in earnings for derivatives not designated as hedges	(31,609)	(50,738)	44,166
Not Designated as Hedging Instruments | Relating to underwriting portfolio: | Other underwriting-related contracts | Other insurance related income (loss)
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]
Unrealized and realized gains (loss) recognized in earnings for derivatives not designated as hedges	$ 3,542	$ 2,742	$ (9,035)