RESERVES FOR LOSSES AND LAE - Schedule of Activity in the Reserve for Losses and Loss Adjustment Expenses (“LAE”) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves beginning of period	$ 14,977	$ 13,121	$ 11,578
Less reinsurance recoverables on unpaid losses	(3,684)	(3,651)	(3,951)
Net reserves beginning of period	12,614	11,294	9,470	$ 7,627
Current year	5,599	5,815	5,382
Prior years	(21)	7	5
Total incurred losses and LAE	5,578	5,823	5,387
Current year	1,169	1,097	2,374
Prior years	3,128	2,867	1,127
Total paid losses and LAE	4,298	3,964	3,501
Foreign exchange/translation adjustment	40	(35)	(42)
Net reserves end of period	12,614	11,294	9,470
Plus reinsurance recoverables on unpaid losses	3,182	3,684	3,651
Gross reserves end of period	$ 15,796	$ 14,977	$ 13,121