SIGNIFICANT ACCOUNTING POLICIES - ACCRUED AND OTHER LIABILITIES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Intangible assets
Impairment charges related to finite-lived intangible assets	$ 0.0	$ 0.0	$ 0.0
Impairment charges related to indefinite-lived intangible assets and goodwill for impairment	0.0	0.0	$ 0.0
Accrued and other liabilities
Payroll and vacation	35.8	29.2
Employee incentives and other benefits	32.2	25.9
Insurance reserves and other related liabilities - short term	9.0	7.0
Multi-employer withdrawal liability - short-term (see Note 12)	4.1	10.6
Income tax and other tax related liabilities	3.1	11.7
Other short-term liabilities	17.2	12.4
Total	101.4	96.8
Other long-term liabilities
Multi-employer withdrawal liability (see Note 12)	50.8	52.8
Pension and post-retirement liabilities (see Note 11)	43.3	82.0
Insurance reserves and other related liabilities	26.9	25.4
Other long-term liabilities	10.0	5.6
Total	$ 131.0	$ 165.8
Customer Relationships | Maximum
Intangible assets
Expected useful lives	21 years