LEASES - Lease expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Lease expense
Operating lease cost	$ 10.2	$ 10.3
Short-term lease cost	0.3	0.6
Variable lease cost	0.2	1.9
Total	$ 10.7	12.8
Remaining lease term - operating leases	11 years 3 months 18 days
Discount rate - operating leases	5.20%
Supplemental cash flow information related to leases was as follows:
Operating cash flows from operating leases	$ 14.4	15.3
Operating leases - Right-of-use assets obtained in exchange for lease obligations	$ 2.6	$ 8.6