SUPPLEMENTAL GUARANTOR FINANCIAL INFORMATION (Statements of Operations)(Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended		95 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018
Supplemental Guarantor Financial Information Statement of Operations [Line Items]
Sales	$ 1,872.4			$ 1,554.9			$ 5,311.1	$ 4,648.5
Operating expenses:
Cost of goods sold	1,441.7			1,349.3			4,431.1	4,154.7
Selling and administration	110.8			91.1			321.6	268.8
Restructuring charges	3.3	$ 6.4	$ 4.0	9.2	$ 8.5	$ 8.2	13.7	25.9	$ 200.9
Acquisition-related costs	0.4			1.1			1.0	12.5
Other operating income (expense)	(1.7)			0.0			6.4	(0.1)
Operating (loss) income	(314.5)			(104.2)			(550.1)	(186.5)
Earnings (losses) of non-consolidated affiliates	0.4			0.5			(20.2)	1.5
Equity income in subsidiaries	0.0			0.0			0.0	0.0
Interest expense	59.2			53.1			184.0	158.0
Interest income	0.3			0.4			1.1	1.0
Non-operating pension income (expense)	5.4			8.4			16.2	25.5
Income before taxes	261.4			60.4			363.2	56.5
Income tax (benefit) provision	66.3			7.7			88.6	(3.7)
Net income	195.1			52.7			274.6	60.2
Parent Guarantor
Supplemental Guarantor Financial Information Statement of Operations [Line Items]
Sales	360.9			348.0			1,083.1	1,000.9
Operating expenses:
Cost of goods sold	208.3			318.5			853.2	897.6
Selling and administration	51.4			35.8			151.7	113.9
Restructuring charges	0.0			0.0			0.0	0.0
Acquisition-related costs	0.4			1.1			1.0	12.5
Other operating income (expense)	(3.5)			(2.6)			(0.9)	(7.1)
Operating (loss) income	(97.3)			10.0			(76.3)	30.2
Earnings (losses) of non-consolidated affiliates	0.4			0.5			(20.2)	1.5
Equity income in subsidiaries	122.2			54.5			249.1	72.9
Interest expense	17.3			11.9			52.4	33.3
Interest income	1.8			1.7			4.7	4.7
Non-operating pension income (expense)	6.5			9.4			19.9	28.5
Income before taxes	210.9			44.2			277.4	44.1
Income tax (benefit) provision	15.8			(8.5)			2.8	(16.1)
Net income	195.1			52.7			274.6	60.2
Issuer
Supplemental Guarantor Financial Information Statement of Operations [Line Items]
Sales	0.0			0.0			0.0	0.0
Operating expenses:
Cost of goods sold	0.0			0.0			0.0	0.0
Selling and administration	0.0			0.0			0.0	0.0
Restructuring charges	0.0			0.0			0.0	0.0
Acquisition-related costs	0.0			0.0			0.0	0.0
Other operating income (expense)	0.0			0.0			0.0	0.0
Operating (loss) income	0.0			0.0			0.0	0.0
Earnings (losses) of non-consolidated affiliates	0.0			0.0			0.0	0.0
Equity income in subsidiaries	85.2			54.7			195.5	94.0
Interest expense	37.3			41.0			116.4	123.8
Interest income	0.0			0.0			0.0	0.0
Non-operating pension income (expense)	0.0			0.0			0.0	0.0
Income before taxes	47.9			13.7			79.1	(29.8)
Income tax (benefit) provision	(9.1)			(15.0)			(28.2)	(45.7)
Net income	57.0			28.7			107.3	15.9
Subsidiary Non-Guarantor
Supplemental Guarantor Financial Information Statement of Operations [Line Items]
Sales	1,621.7			1,321.8			4,554.6	3,976.9
Operating expenses:
Cost of goods sold	1,343.6			1,145.7			3,904.5	3,586.4
Selling and administration	59.4			55.3			169.9	154.9
Restructuring charges	3.3			9.2			13.7	25.9
Acquisition-related costs	0.0			0.0			0.0	0.0
Other operating income (expense)	1.8			2.6			7.3	7.0
Operating (loss) income	(217.2)			(114.2)			(473.8)	(216.7)
Earnings (losses) of non-consolidated affiliates	0.0			0.0			0.0	0.0
Equity income in subsidiaries	0.0			0.0			0.0	0.0
Interest expense	6.1			1.5			19.6	5.5
Interest income	0.0			0.0			0.8	0.9
Non-operating pension income (expense)	(1.1)			(1.0)			(3.7)	(3.0)
Income before taxes	210.0			111.7			451.3	209.1
Income tax (benefit) provision	59.6			31.2			114.0	58.1
Net income	150.4			80.5			337.3	151.0
Eliminations
Supplemental Guarantor Financial Information Statement of Operations [Line Items]
Sales	(110.2)			(114.9)			(326.6)	(329.3)
Operating expenses:
Cost of goods sold	(110.2)			(114.9)			(326.6)	(329.3)
Selling and administration	0.0			0.0			0.0	0.0
Restructuring charges	0.0			0.0			0.0	0.0
Acquisition-related costs	0.0			0.0			0.0	0.0
Other operating income (expense)	0.0			0.0			0.0	0.0
Operating (loss) income	0.0			0.0			0.0	0.0
Earnings (losses) of non-consolidated affiliates	0.0			0.0			0.0	0.0
Equity income in subsidiaries	(207.4)			(109.2)			(444.6)	(166.9)
Interest expense	(1.5)			(1.3)			(4.4)	(4.6)
Interest income	(1.5)			(1.3)			(4.4)	(4.6)
Non-operating pension income (expense)	0.0			0.0			0.0	0.0
Income before taxes	(207.4)			(109.2)			(444.6)	(166.9)
Income tax (benefit) provision	0.0			0.0			0.0	0.0
Net income	$ (207.4)			$ (109.2)			$ (444.6)	$ (166.9)