ACCOUNTS PAYABLE AND ACCRUED LIABILITIES - Schedule of accounts payable and accrued liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
ACCOUNTS PAYABLE AND ACCRUED LIABILITIES
Compensation and benefit-related liabilities	$ 42.1	$ 18.0
Termination benefits	2.2	4.8
Royalties	17.9	20.3
Accrued liabilities	83.7	59.1
Marketing fee payable	13.9	8.4
Accounts payable	11.1	43.2
Total accounts payable and accrued liabilities	$ 170.9	$ 153.8