SIGNIFICANT ACCOUNTING POLICIES - OTHER LIABILITIES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
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
Impairment charges related to investment in SSAT	0.0	0.0	$ 0.0
Accrued and other liabilities
Employee incentives and other benefits	27.9	36.6
Payroll and vacation	36.2	36.1
Insurance reserves and other related liabilities - short term	29.3	27.2
Income tax and other tax related liabilities	6.0	8.6
Deferred revenues	5.7	5.5
Multi-employer withdrawal liabilities - short term	4.1	4.1
Other short-term liabilities	5.1	5.1
Total	114.3	123.2
Other long-term liabilities
Multi-employer withdrawal liability	41.9	44.2
Insurance reserves and other related liabilities	13.8	25.6
Pension and post-retirement liabilities	16.1	21.3
Income tax liabilities	7.0	9.1
Other long-term liabilities	9.6	9.1
Total	$ 88.4	$ 109.3
Customer Relationships | Maximum
Intangible assets
Expected useful lives	21 years