ACQUISITIONS AND BUSINESS COMBINATIONS - Summary of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions		6 Months Ended
	Feb. 24, 2020	Jun. 30, 2021	Jun. 30, 2020
Business Acquisition [Line Items]
Acquisitions funded by deferred consideration		$ 0.0	$ 1.7
Coram Material Corp.
Business Acquisition [Line Items]
Accounts receivable	$ 2.0
Inventory	10.0
Other current assets	0.3
Property, plant and equipment	130.9
Total assets acquired	143.2
Current liabilities	0.1
Other long-term liabilities	0.2
Total liabilities assumed	0.3
Total consideration (fair value)	142.9
Consideration satisfied in cash	140.2	1.0
Acquisitions funded by deferred consideration	1.7
Working capital adjustment	1.6
Accounts payable	0.6	$ 0.6
Consideration transferred, liabilities incurred	$ 2.0