LEASE - COMPONENTS OF LEASE COST AND OTHER INFORMATION (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Lease Cost
Operating lease cost	$ 16.8	$ 33.5
Short-term lease cost	2.5	4.9
Variable lease cost	0.1	0.2
Total lease cost	19.4	38.6
Cash paid for amounts included in operating lease liabilities	16.6	33.3
Right of use assets obtained in the exchange for new operating lease liabilities	$ 9.4	$ 15.2
Weighted-average remaining operating lease term	7 years 9 months 18 days	7 years 9 months 18 days
Weighted-average incremental borrowing rate	4.40%	4.40%