PENSION AND POST-RETIREMENT BENEFITS - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (income) costs	$ 1.2	$ (0.1)	$ 1.1	$ (0.4)		$ 0.6
Estimated contributions in next fiscal year	10.0		10.0
Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (income) costs					$ 3.0
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (income) costs	1.0	(0.3)	0.7	(0.7)
Employer contributions	1.8		3.5
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	0.4	$ 0.3
Employer contributions	$ 0.2		$ 0.4