GOODWILL AND INTANGIBLE ASSETS - Schedule of Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill [Line Items]
Goodwill, gross	$ 242.5	$ 242.5	$ 239.7
Accumulated impairment	(241.7)	(241.7)	(218.6)
Goodwill	0.8	0.8	21.1	$ 234.8
Intangible assets	223.5	223.5	260.5
Less: accumulated amortization - other intangible assets	21.0	21.0	13.1
Intangible assets, net	202.5	202.5	247.4
Other Intangible Assets (Definite-Lived)
Goodwill [Line Items]
Intangible assets	23.8	23.8	23.8
Franchise Rights
Goodwill [Line Items]
Intangible assets	199.7	199.7	236.7
Impairment of indefinite-lived intangible assets	$ 37.0	$ 142.7	$ 105.7