MARKETABLE SECURITIES - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Available-for-sale equity securities				$ 20.0
Equity securities, realized gain		$ 1.1
Unrealized (loss) gain recorded in other income	$ 1.5		$ 10.6
Losses recorded on securities intended to be sold		15.3	5.8
Unrealized Gains/(Losses) on Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Losses recorded on securities intended to be sold		1.2	$ 0.0
CYAPC and YAEC
Debt Securities, Available-for-sale [Line Items]
Available-for-sale equity securities		168.3		170.1
Marketable securities held in nuclear decommissioning trust		$ 162.2		$ 163.2