SHAREHOLDERS' EQUITY (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amortization of Net Loss [Member]
Amounts recognized as a component of net periodic pension and other postretirement benefit cost:
Total before income taxes	$ (19.3)	$ (29.8)	$ (21.9)
Amortization of Prior Service Credit [Member]
Amounts recognized as a component of net periodic pension and other postretirement benefit cost:
Total before income taxes	26.4	18.4	10.7
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Amounts recognized as a component of net periodic pension and other postretirement benefit cost:
Total before income taxes	7.1	(11.4)	(11.2)
Income tax (expense) benefit	(1.5)	0.0	3.8
Total reclassifications for the period, net of income taxes	$ 5.6	$ (11.4)	$ (7.4)