GOODWILL AND OTHER INTANGIBLE ASSETS - Schedule of Purchased Intangible Assets (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Gross	$ 186.6	$ 190.6
Accumulated Amortization	(105.9)	(99.4)
Total	$ 80.7	$ 91.2
Weighted Average Remaining Life (In Years)	9 years 7 months 6 days	9 years 4 months 24 days
Total purchased intangible assets, Gross	$ 187.8	$ 191.8
Total purchased intangible assets, Accumulated Amortization	(105.9)	(99.4)
Total purchased intangible assets, Net	81.9	92.4
Land rights
Acquired Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	1.2	1.2
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross	108.5	108.5
Accumulated Amortization	(67.4)	(59.7)
Total	$ 41.1	$ 48.8
Weighted Average Remaining Life (In Years)	3 years 6 months	3 years 10 months 24 days
Total purchased intangible assets, Accumulated Amortization	$ (67.4)	$ (59.7)
Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross	44.5	44.5
Accumulated Amortization	(14.5)	(13.6)
Total	$ 30.0	$ 30.9
Weighted Average Remaining Life (In Years)	18 years 8 months 12 days	19 years 1 month 6 days
Total purchased intangible assets, Accumulated Amortization	$ (14.5)	$ (13.6)
Non-competes
Acquired Finite-Lived Intangible Assets [Line Items]
Gross	18.3	18.3
Accumulated Amortization	(16.1)	(15.3)
Total	$ 2.2	$ 3.0
Weighted Average Remaining Life (In Years)	2 years 2 months 12 days	2 years 4 months 24 days
Total purchased intangible assets, Accumulated Amortization	$ (16.1)	$ (15.3)
Leasehold interests
Acquired Finite-Lived Intangible Assets [Line Items]
Gross	12.5	12.5
Accumulated Amortization	(7.6)	(6.7)
Total	$ 4.9	$ 5.8
Weighted Average Remaining Life (In Years)	5 years 2 months 12 days	5 years 4 months 24 days
Total purchased intangible assets, Accumulated Amortization	$ (7.6)	$ (6.7)
Favorable contracts
Acquired Finite-Lived Intangible Assets [Line Items]
Gross		4.0
Accumulated Amortization		(3.9)
Total		$ 0.1
Weighted Average Remaining Life (In Years)		10 months 24 days
Total purchased intangible assets, Accumulated Amortization		$ (3.9)
Environmental credits
Acquired Finite-Lived Intangible Assets [Line Items]
Gross	2.8	2.8
Accumulated Amortization	(0.3)	(0.2)
Total	$ 2.5	$ 2.6
Weighted Average Remaining Life (In Years)	15 years 6 months	16 years
Total purchased intangible assets, Accumulated Amortization	$ (0.3)	$ (0.2)