MARKETABLE SECURITIES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 20.0	$ 40.2
Unrealized losses recorded in other income	9.7
Unrealized gains recorded in other income		4.4	$ 3.7
CYAPC and YAEC
Debt Securities, Available-for-sale [Line Items]
Equity securities	170.1	214.0
Marketable securities held in nuclear decommissioning trusts	$ 163.2	$ 189.9