ACQUISITIONS AND BUSINESS COMBINATIONS - Schedule of Adjustments Reflected in Pro Forma Net Income (Loss) and Net Income (Loss) Per Share Amounts (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Increase in depreciation, depletion and amortization expense			$ (50.1)	$ (48.6)
Increase in interest expense	$ (10.3)	$ (11.4)	(20.7)	(22.8)
Increase in income tax expense	$ 0.7	(4.3)	$ 5.4	0.6
Coram Material Corp. | Acquisition-related costs
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Decrease in cost of goods sold related to fair value increase in inventory		2.6		4.2
Increase in depreciation, depletion and amortization expense		0.0		(0.9)
Exclusion of buyer transaction costs		0.1		0.6
Exclusion of seller transaction costs		0.0		0.3
Increase in interest expense		0.0		(0.8)
Increase in income tax expense		$ 0.0		$ (1.1)