CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended								12 Months Ended			98 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018
Income Statement [Abstract]
Sales	$ 1,635.0	$ 1,872.4	$ 1,728.4	$ 1,710.3	$ 1,619.9	$ 1,554.9	$ 1,526.5	$ 1,567.1	$ 6,946.1	$ 6,268.4	$ 5,550.6
Operating expenses:
Cost of goods sold	1,391.0	1,441.7	1,460.7	1,528.7	1,400.2	1,349.3	1,407.9	1,397.5	5,822.1	5,554.9	4,944.5
Selling and administration									430.6	369.8	347.2
Restructuring charges									21.9	37.6	112.9	$ 209.1
Acquisition-related costs									1.0	12.8	48.8
Other operating income									6.4	3.3	10.6
Operating income									676.9	296.6	107.8
Earnings (losses) of non-consolidated affiliates									(19.7)	1.8	1.7
Interest expense									243.2	217.4	191.9
Interest income									1.6	1.8	3.4
Non-operating pension income									21.7	34.4	44.8
Income (loss) before taxes									437.3	117.2	(34.2)
Income tax provision (benefit)									109.4	(432.3)	(30.3)
Net income (loss)	$ 53.3	$ 195.1	$ 58.6	$ 20.9	$ 489.3	$ 52.7	$ (5.9)	$ 13.4	$ 327.9	$ 549.5	$ (3.9)
Net income (loss) per common share:
Basic	$ 0.32	$ 1.17	$ 0.35	$ 0.13	$ 2.93	$ 0.32	$ (0.04)	$ 0.08	$ 1.97	$ 3.31	$ (0.02)
Diluted	$ 0.32	$ 1.16	$ 0.35	$ 0.12	$ 2.89	$ 0.31	$ (0.04)	$ 0.08	$ 1.95	$ 3.26	$ (0.02)
Average common shares outstanding:
Basic									166.8	166.2	165.2
Diluted									168.4	168.5	165.2