PENSION AND POST-RETIREMENT BENEFITS - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (income) costs	$ 2.0	$ 0.6	$ 2.6
Net periodic benefit (income) costs next fiscal year	7.9
Estimated contributions in next fiscal year	12.0
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (income) costs	1.8	0.4
Employer contributions	1.6
Other Post-Retirement Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (income) costs	0.2	$ 0.2
Employer contributions	$ 0.2