LEASES - Components of Lease Cost (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lease, Cost [Abstract]
Operating lease cost	$ 6.8	$ 13.7
Short-term lease cost	0.5	0.6
Sublease income	0.0	(0.1)
Total lease cost	$ 7.3	$ 14.2