DISPOSITIONS AND SPECIAL GAINS AND CHARGES - Discontinued Operations (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income (loss) from discontinued operations	$ 1.3	$ (1.5)	$ 175.2
Net income (loss) per share - basic (in dollars per share)	$ 0.03	$ (0.04)	$ 4.69
Net income (loss) per share - diluted (in dollars per share)	$ 0.03	$ (0.04)	$ 4.62
NATG
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	$ 0.0	$ 0.0	$ 352.0
Cost of sales	0.0	0.0	295.8
Gross profit	0.0	0.0	56.2
Selling, distribution and administrative expenses	(0.4)	2.1	36.5
Pre-tax book gain on sale of France business	0.0	0.0	(178.9)
Special (gains) charges, net	(1.4)	0.0	0.6
Operating income (loss) from discontinued operations	1.8	(2.1)	198.0
Foreign currency exchange income	0.0	0.0	(0.2)
Income (loss) of discontinued operations before income taxes	1.8	(2.1)	198.2
Provision (benefit) for income taxes	0.5	(0.6)	23.0
Net income (loss) from discontinued operations	$ 1.3	$ (1.5)	$ 175.2
Net income (loss) per share - basic (in dollars per share)	$ 0.03	$ (0.04)	$ 4.69
Net income (loss) per share - diluted (in dollars per share)	$ 0.03	$ (0.04)	$ 4.62