INCOME TAXES - Summary of Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income (loss) before income taxes
Bermuda (domestic)	$ 323,688	$ 213,539	$ 236,781
Foreign	702,503	189,067	8,340
Total income before income taxes	$ 1,026,191	$ 402,606	$ 245,121
Reconciliation of effective tax rate (% of income before income taxes)
Expected tax rate	0.00%	0.00%	0.00%
Valuation allowance	(1.40%)	(2.00%)	9.50%
Prior year adjustments	(1.50%)	1.30%	(0.30%)
Incremental branch taxes	1.10%	0.90%	(0.40%)
Change in enacted tax rate	(1.90%)	(3.30%)	(2.20%)
Bermuda economic transition adjustment	(17.20%)	0.00%	0.00%
Change in unrealized investment gain/(loss)	0.60%	0.00%	0.00%
Withholding tax	0.30%	0.00%	0.00%
Other	0.20%	0.20%	0.30%
Actual tax rate	(5.40%)	6.50%	9.00%
U.S.
Reconciliation of effective tax rate (% of income before income taxes)
Foreign taxes at local expected rates	8.40%	(2.50%)	0.20%
Europe
Reconciliation of effective tax rate (% of income before income taxes)
Foreign taxes at local expected rates	6.00%	11.90%	1.90%
United Kingdom
Reconciliation of effective tax rate (% of income before income taxes)
Expected tax rate			25.00%	19.00%
Belgium
Reconciliation of effective tax rate (% of income before income taxes)
Expected tax rate			25.00%	30.00%