Condensed Consolidating Financial Statements (Statements of Operations and Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Income Statements, Captions [Line Items]
Net sales	$ 891.8	$ 1,052.3	$ 1,102.1	$ 793.4	$ 897.3	$ 1,010.0	$ 1,019.2	$ 715.2	$ 3,839.6	$ 3,641.6	$ 3,467.4
Cost of goods sold									2,714.4	2,565.1	2,520.0
Gross profit	259.8	313.7	340.8	210.9	267.6	310.3	315.0	183.6	1,125.2	1,076.5	947.4
Operating expenses:
Selling, general and administrative expenses									637.7	621.0	580.5
Losses (gains) and other expenses, net									8.2	11.3	21.7
Restructuring charges									3.2	1.8	3.2
Goodwill impairment									0.0	0.0	5.5
Asset impairment									0.0	0.0	44.5
Pension settlement									0.0	31.4	0.0
Income from equity method investments									(18.4)	(18.4)	(13.4)
Operating income									494.5	429.4	305.4
Interest expense, net									30.6	27.0	23.6
Other income, net									(0.1)	(0.3)	(0.8)
Income from continuing operations before income taxes									464.0	402.7	282.6
Provision for income taxes									156.9	124.1	95.4
Income from continuing operations									307.1	278.6	187.2
Loss from discontinued operations									(1.4)	(0.8)	(0.6)
Net income	$ 43.1	$ 103.5	$ 115.5	$ 43.5	$ 40.4	$ 101.7	$ 110.7	$ 24.9	305.7	277.8	186.6
Other comprehensive income (loss), net of tax									37.7	9.6	(51.2)
Comprehensive income									343.4	287.4	135.4
Parent [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									0.0	0.0	0.0
Cost of goods sold									0.0	0.0	0.0
Gross profit									0.0	0.0	0.0
Operating expenses:
Selling, general and administrative expenses									0.0	0.0	0.0
Losses (gains) and other expenses, net									2.0	(3.3)	0.7
Restructuring charges									0.0	0.0	0.0
Goodwill impairment									0.0	0.0	0.0
Asset impairment									0.0	0.0	0.0
Pension settlement									0.0	0.0	0.0
Income from equity method investments									(324.3)	(292.4)	(201.8)
Operating income									322.3	295.7	201.1
Interest expense, net									26.9	24.4	22.4
Other income, net									0.0	0.0	0.0
Income from continuing operations before income taxes									295.4	271.3	178.7
Provision for income taxes									(10.3)	(6.5)	(7.8)
Income from continuing operations									305.7	277.8	186.5
Loss from discontinued operations									0.0	0.0	0.0
Net income									305.7	277.8	186.5
Other comprehensive income (loss), net of tax									1.7	14.0	(3.5)
Comprehensive income									307.4	291.8	183.0
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									3,295.8	3,117.6	2,950.6
Cost of goods sold									2,359.6	2,203.8	2,150.9
Gross profit									936.2	913.8	799.7
Operating expenses:
Selling, general and administrative expenses									553.6	524.3	485.6
Losses (gains) and other expenses, net									4.4	9.7	13.7
Restructuring charges									2.1	1.9	(0.5)
Goodwill impairment									0.0	0.0	5.5
Asset impairment									0.0	0.0	44.5
Pension settlement									0.0	30.5	0.0
Income from equity method investments									(74.9)	(40.7)	(5.9)
Operating income									451.0	388.1	256.8
Interest expense, net									(2.7)	(2.2)	(2.0)
Other income, net									0.0	0.0	0.0
Income from continuing operations before income taxes									453.7	390.3	258.8
Provision for income taxes									136.2	108.2	87.9
Income from continuing operations									317.5	282.1	170.9
Loss from discontinued operations									0.0	0.0	0.0
Net income									317.5	282.1	170.9
Other comprehensive income (loss), net of tax									5.5	8.5	(3.3)
Comprehensive income									323.0	290.6	167.6
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									1,144.2	728.0	701.8
Cost of goods sold									953.6	564.5	556.4
Gross profit									190.6	163.5	145.4
Operating expenses:
Selling, general and administrative expenses									85.0	96.7	94.9
Losses (gains) and other expenses, net									1.9	5.1	7.5
Restructuring charges									1.1	(0.1)	3.7
Goodwill impairment									0.0	0.0	0.0
Asset impairment									0.0	0.0	0.0
Pension settlement									0.0	0.9	0.0
Income from equity method investments									(14.5)	(14.4)	(10.5)
Operating income									117.1	75.3	49.8
Interest expense, net									6.4	4.8	3.2
Other income, net									(0.1)	(0.3)	(0.8)
Income from continuing operations before income taxes									110.8	70.8	47.4
Provision for income taxes									31.2	22.6	14.3
Income from continuing operations									79.6	48.2	33.1
Loss from discontinued operations									(1.4)	(0.8)	(0.6)
Net income									78.2	47.4	32.5
Other comprehensive income (loss), net of tax									30.5	(14.2)	(40.4)
Comprehensive income									108.7	33.2	(7.9)
Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Net sales									(600.4)	(204.0)	(185.0)
Cost of goods sold									(598.8)	(203.2)	(187.3)
Gross profit									(1.6)	(0.8)	2.3
Operating expenses:
Selling, general and administrative expenses									(0.9)	0.0	0.0
Losses (gains) and other expenses, net									(0.1)	(0.2)	(0.2)
Restructuring charges									0.0	0.0	0.0
Goodwill impairment									0.0	0.0	0.0
Asset impairment									0.0	0.0	0.0
Pension settlement									0.0	0.0	0.0
Income from equity method investments									395.3	329.1	204.8
Operating income									(395.9)	(329.7)	(202.3)
Interest expense, net									0.0	0.0	0.0
Other income, net									0.0	0.0	0.0
Income from continuing operations before income taxes									(395.9)	(329.7)	(202.3)
Provision for income taxes									(0.2)	(0.2)	1.0
Income from continuing operations									(395.7)	(329.5)	(203.3)
Loss from discontinued operations									0.0	0.0	0.0
Net income									(395.7)	(329.5)	(203.3)
Other comprehensive income (loss), net of tax									0.0	1.3	(4.0)
Comprehensive income									$ (395.7)	$ (328.2)	$ (207.3)