RELATED PARTY TRANSACTIONS - Expenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Total expenses	$ 7,315.0	$ 6,503.1	$ 6,369.6
Related Party
Related Party Transaction [Line Items]
Total expenses	52.8	46.2	65.4
Dofcon | Related Party
Related Party Transaction [Line Items]
Total expenses	25.3	14.4	26.7
Others | Related Party
Related Party Transaction [Line Items]
Total expenses	$ 27.5	$ 31.8	$ 38.7