CREDIT FACILITIES - Schedule of Long-Term Debt Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024
Line of Credit Facility [Line Items]
Finance lease obligations (see note 7)	$ 61.5	$ 61.7
Total Credit Facility and finance lease obligations:	784.1	796.7
Current portion	27.4	26.5
Long-term portion	756.7	770.2
Line of Credit
Line of Credit Facility [Line Items]
Total borrowings under Credit Facility	728.1	741.2
Line of Credit | Letter of Credit, Guarantees, Surety Bonds, and Overdraft Facilities
Line of Credit Facility [Line Items]
Long-term debt	46.6	34.1
Revolving Facility | Line of Credit
Line of Credit Facility [Line Items]
Total borrowings under Credit Facility	0.0	0.0
Fees and expenses upon amendments to the credit facility			$ 3.9
Revolving Facility | Line of Credit | Interest rate swaps
Line of Credit Facility [Line Items]
Notional amounts under interest rate swaps (note 15)	0.0	0.0
Secured Debt | Line of Credit
Line of Credit Facility [Line Items]
Total borrowings under Credit Facility	728.1	741.2
Unamortized debt issuance costs related to the Term Loans	(5.5)	(6.2)
Total incurred fees deferred			$ 5.4
Secured Debt | Line of Credit | Term A Loan
Line of Credit Facility [Line Items]
Total borrowings under Credit Facility	234.4	243.7
Secured Debt | Line of Credit | Term B Loan
Line of Credit Facility [Line Items]
Total borrowings under Credit Facility	493.7	497.5
Secured Debt | Line of Credit | Interest rate swaps
Line of Credit Facility [Line Items]
Notional amounts under interest rate swaps (note 15)	370.0	330.0
Secured Debt | Line of Credit | Interest rate swaps | Term A Loan
Line of Credit Facility [Line Items]
Notional amounts under interest rate swaps (note 15)	130.0	130.0
Secured Debt | Line of Credit | Interest rate swaps | Term B Loan
Line of Credit Facility [Line Items]
Notional amounts under interest rate swaps (note 15)	240.0	200.0
Letter of Credit | Line of Credit | Letter of Credit, Guarantees, Surety Bonds, and Overdraft Facilities
Line of Credit Facility [Line Items]
Long-term debt	10.8	11.1
Bank Guarantees and Surety Bonds | Line of Credit | Letter of Credit, Guarantees, Surety Bonds, and Overdraft Facilities
Line of Credit Facility [Line Items]
Long-term debt	35.8	23.0
Bank Overdraft Facility | Line of Credit
Line of Credit Facility [Line Items]
Long-term debt	0.0	0.0
Available uncommitted bank overdraft facilities	$ 198.5	$ 198.5