PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Estimated Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 3.4	$ 4.2	$ 12.9	$ 13.2
Interest cost	7.9	7.8	22.9	22.7
Expected return on plan assets	(13.8)	(13.6)	(40.9)	(41.0)
Prior service credits	0.6	0.5	1.9	1.6
Net actuarial loss	6.1	5.4	16.7	15.9
Net periodic benefit credit	4.2	4.3	13.5	12.4
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.3	0.4	1.3	1.3
Interest cost	1.9	2.3	6.2	6.8
Expected return on plan assets	(4.4)	(4.3)	(13.3)	(12.8)
Prior service credits	(0.8)	(0.9)	(2.3)	(2.8)
Net actuarial loss	0.9	1.7	3.4	4.5
Net periodic benefit credit	$ (2.1)	$ (0.8)	$ (4.7)	$ (3.0)