SHAREHOLDERS' EQUITY (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		23 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Apr. 26, 2018
Equity, Class of Treasury Stock [Line Items]
Cost of common stock repurchased and retired (in dollars)	$ 0.0	$ 13.2
Stock options exercised	0.1	0.1
Total value of stock options exercised	$ 0.7	$ 1.4
Foreign Currency Translation Adjustment (net of taxes)
Beginning balance	(8.4)	0.7
Unrealized losses	(9.0)	(8.3)
Reclassification adjustments of losses into income	0.0	0.0
Tax benefit (provision)	0.0	0.0
Net change	(9.0)	(8.3)
Ending Balance	(17.4)	(7.6)	$ (17.4)
Unrealized Gains (Losses) on Derivative Contracts (net of taxes)
Beginning balance	(13.6)	1.8
Unrealized losses	(35.1)	(6.6)
Reclassification adjustments of losses into income	11.6	2.2
Tax benefit (provision)	5.6	1.1
Net change	(17.9)	(3.3)
Ending balance	(31.5)	(1.5)	(31.5)
Pension and Other Postretirement Benefits (net of taxes)
Beginning balance	(781.4)	(653.5)
Unrealized losses	0.0	0.0
Reclassification adjustments of losses into income	11.9	7.4
Tax benefit (provision)	(2.7)	(1.7)
Net change	9.2	5.7
Ending balance	(772.2)	(647.8)	(772.2)
Accumulated Other Comprehensive Loss
Beginning balance	(803.4)	(651.0)
Unrealized losses	(44.1)	(14.9)
Reclassification adjustments of losses into income	23.5	9.6
Tax benefit (provision)	2.9	(0.6)
Net change	(17.7)	(5.9)
Ending balance	(821.1)	(656.9)	(821.1)
2018 Share Repurchase Program | Common Stock
Equity, Class of Treasury Stock [Line Items]
Authorized share repurchase program (in dollars)				$ 500.0
Cost of common stock repurchased and retired (in dollars)		$ 13.2	$ 195.9
Total repurchased shares under this program (in shares)		0.6	10.1
Remaining authorized repurchase amount (in dollars)	$ 304.1		$ 304.1