LEASES - Supplemental Balance Sheet (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
LEASES.
Operating lease right of use assets	$ 111.9	$ 111.7
Current operating lease liabilities	$ 17.9	$ 18.3
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accounts Payable and Accrued Liabilities, Current	Accounts Payable and Accrued Liabilities, Current
Non-current operating lease liabilities	$ 129.0	$ 129.3
Total leased liabilities	$ 146.9	$ 147.6