SHAREHOLDERS' EQUITY (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended				6 Months Ended		14 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Apr. 26, 2018
Equity, Class of Treasury Stock [Line Items]
Cost of common stock repurchased and retired (in dollars)					$ 26.7	$ 9.1
Stock options exercised					0.1	0.2
Total value of stock options exercised	$ 0.1	$ 1.4	$ 1.2	$ 1.0	$ 1.5	$ 2.2
Foreign Currency Translation Adjustment (net of taxes)
Beginning balance		0.7		7.6	0.7	7.6
Unrealized gains (losses)	3.3	(8.3)	(26.1)	12.4
Reclassification adjustments of (gains) losses into income	0.0	0.0	0.0	0.0
Tax benefit (provision)	0.0	0.0	0.0	0.0
Net change					(5.0)	(13.7)
Income tax reclassification adjustment				15.3
Ending Balance	(4.3)		9.2		(4.3)	9.2	$ (4.3)
Unrealized Gains (Losses) on Derivative Contracts (net of taxes)
Beginning balance		1.8		11.1	1.8	11.1
Unrealized gains (losses)	(22.2)	(6.6)	(0.4)	2.1
Reclassification adjustments of (gains) losses into income	6.3	2.2	(2.7)	(2.3)
Tax benefit (provision)	3.8	1.1	0.7	0.1
Net change	(12.1)		(2.4)		(15.4)	(2.5)
Income tax reclassification adjustment				2.4
Ending balance	(13.6)		11.0		(13.6)	11.0	(13.6)
Pension and Other Postretirement Benefits (net of taxes)
Beginning balance		(653.5)		(503.3)	(653.5)	(503.3)
Unrealized gains (losses)	0.0	0.0	0.0	0.0
Reclassification adjustments of (gains) losses into income	7.1	7.4	9.1	9.4
Tax benefit (provision)	(1.8)	(1.7)	(1.0)	(4.0)
Net change					11.0	13.5
Income tax reclassification adjustment				(103.6)
Ending balance	(642.5)		(593.4)		(642.5)	(593.4)	(642.5)
Accumulated Other Comprehensive Loss
Beginning balance		(651.0)		(484.6)	(651.0)	(484.6)
Unrealized gains (losses)	(18.9)	(14.9)	(26.5)	14.5
Reclassification adjustments of (gains) losses into income	13.4	9.6	6.4	7.1
Tax benefit (provision)	2.0	$ (0.6)	(0.3)	(3.9)
Net change					(9.4)	(2.7)
Income tax reclassification adjustment				$ (85.9)
Ending balance	(660.4)		$ (573.2)		$ (660.4)	$ (573.2)	$ (660.4)
2018 Share Repurchase Program | Common Stock
Equity, Class of Treasury Stock [Line Items]
Authorized share repurchase program (in dollars)								$ 500.0
Total repurchased shares under this program (in shares)					1.2	0.3	3.3
Cost of common stock repurchased and retired (in dollars)					$ 26.7	$ 9.1	$ 76.8
Remaining authorized repurchase amount (in dollars)	$ 423.2				$ 423.2		$ 423.2