INCOME TAXES - Summary of Current and Deferred Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 8.5	$ 4.3	$ 11.7
State	5.3	2.1	2.4
Foreign	10.9	13.7	3.9
Total current	24.7	20.1	18.0
Deferred:
Federal	(0.7)	6.3	(20.6)
State	(0.4)	0.9	2.5
Foreign	(0.2)	(2.4)	(1.5)
Total deferred	(1.3)	4.8	(19.6)
Income tax expense (benefit)	$ 23.4	$ 24.9	$ (1.6)