Condensed Consolidating Financial Statements (Statements of Operations and Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Consolidating Statements of Operations
Net sales	$ 1,052.3	$ 1,010.0	$ 2,947.9	$ 2,744.4
Cost of goods sold	738.6	699.7	2,082.4	1,935.5
Gross profit	313.7	310.3	865.5	808.9
Operating Expenses:
Selling, general and administrative expenses	158.7	156.5	479.6	456.2
Losses and other expenses, net	3.0	0.7	8.5	5.5
Restructuring charges	1.9	0.6	2.1	1.2
Income from equity method investments	(4.5)	(4.4)	(15.5)	(15.3)
Operating income	154.6	156.9	390.8	361.3
Interest expense, net	7.6	7.0	23.3	19.6
Other expense, net	0.0	0.0	(0.2)	(0.2)
Income from continuing operations before income taxes	147.0	149.9	367.7	341.9
Income tax benefit	43.0	48.2	103.8	104.0
Income from continuing operations	104.0	101.7	263.9	237.9
Loss from discontinued operations	(0.5)	0.0	(1.4)	(0.6)
Net income	103.5	101.7	262.5	237.3
Other comprehensive income (loss), net of tax	9.4	(0.4)	38.1	17.7
Comprehensive income	112.9	101.3	300.6	255.0
Eliminations [Member]
Condensed Consolidating Statements of Operations
Net sales	(153.3)	(47.4)	(482.4)	(138.5)
Cost of goods sold	(155.2)	(47.4)	(479.5)	(136.4)
Gross profit	1.9	0.0	(2.9)	(2.1)
Operating Expenses:
Selling, general and administrative expenses	(0.8)	0.0	(1.2)	0.0
Losses and other expenses, net	0.0	0.0	(0.1)	(0.1)
Restructuring charges	0.0	0.0	0.0	0.0
Income from equity method investments	128.9	113.8	326.7	265.1
Operating income	(126.2)	(113.8)	(328.3)	(267.1)
Interest expense, net	0.0	0.0	0.0	0.0
Other expense, net	(0.2)	0.0	(0.2)	0.0
Income from continuing operations before income taxes	(126.0)	(113.8)	(328.1)	(267.1)
Income tax benefit	0.7	0.0	(0.2)	(0.7)
Income from continuing operations	(126.7)	(113.8)	(327.9)	(266.4)
Loss from discontinued operations	0.0	0.0	0.0	0.0
Net income	(126.7)	(113.8)	(327.9)	(266.4)
Other comprehensive income (loss), net of tax	0.0	(0.4)	0.0	1.3
Comprehensive income	(126.7)	(114.2)	(327.9)	(265.1)
Parent [Member]
Condensed Consolidating Statements of Operations
Net sales	0.0	0.0	0.0	0.0
Cost of goods sold	0.0	0.0	0.0	0.0
Gross profit	0.0	0.0	0.0	0.0
Operating Expenses:
Selling, general and administrative expenses	0.0	0.0	0.0	0.0
Losses and other expenses, net	0.2	(1.1)	1.1	(1.7)
Restructuring charges	0.0	0.0	0.0	0.0
Income from equity method investments	(108.2)	(105.0)	(277.5)	(248.5)
Operating income	108.0	106.1	276.4	250.2
Interest expense, net	6.2	6.1	20.9	17.7
Other expense, net	0.0	0.0	0.0	0.0
Income from continuing operations before income taxes	101.8	100.0	255.5	232.5
Income tax benefit	(1.7)	(1.7)	(7.0)	(4.9)
Income from continuing operations	103.5	101.7	262.5	237.4
Loss from discontinued operations	0.0	0.0	0.0	0.0
Net income	103.5	101.7	262.5	237.4
Other comprehensive income (loss), net of tax	0.4	2.7	0.5	7.7
Comprehensive income	103.9	104.4	263.0	245.1
Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Operations
Net sales	905.6	870.5	2,560.6	2,368.8
Cost of goods sold	644.8	603.4	1,830.8	1,675.6
Gross profit	260.8	267.1	729.8	693.2
Operating Expenses:
Selling, general and administrative expenses	140.7	135.9	419.2	394.6
Losses and other expenses, net	1.9	1.1	5.8	4.3
Restructuring charges	1.2	0.5	1.3	1.5
Income from equity method investments	(21.7)	(10.0)	(52.0)	(19.5)
Operating income	138.7	139.6	355.5	312.3
Interest expense, net	(0.6)	(0.5)	(2.3)	(1.5)
Other expense, net	0.0	0.0	0.0	0.0
Income from continuing operations before income taxes	139.3	140.1	357.8	313.8
Income tax benefit	30.5	42.3	84.8	89.1
Income from continuing operations	108.8	97.8	273.0	224.7
Loss from discontinued operations	0.0	0.0	0.0	0.0
Net income	108.8	97.8	273.0	224.7
Other comprehensive income (loss), net of tax	2.1	(0.4)	9.7	2.0
Comprehensive income	110.9	97.4	282.7	226.7
Non-Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Operations
Net sales	300.0	186.9	869.7	514.1
Cost of goods sold	249.0	143.7	731.1	396.3
Gross profit	51.0	43.2	138.6	117.8
Operating Expenses:
Selling, general and administrative expenses	18.8	20.6	61.6	61.6
Losses and other expenses, net	0.9	0.7	1.7	3.0
Restructuring charges	0.7	0.1	0.8	(0.3)
Income from equity method investments	(3.5)	(3.2)	(12.7)	(12.4)
Operating income	34.1	25.0	87.2	65.9
Interest expense, net	2.0	1.4	4.7	3.4
Other expense, net	0.2	0.0	0.0	(0.2)
Income from continuing operations before income taxes	31.9	23.6	82.5	62.7
Income tax benefit	13.5	7.6	26.2	20.5
Income from continuing operations	18.4	16.0	56.3	42.2
Loss from discontinued operations	(0.5)	0.0	(1.4)	(0.6)
Net income	17.9	16.0	54.9	41.6
Other comprehensive income (loss), net of tax	6.9	(2.3)	27.9	6.7
Comprehensive income	$ 24.8	$ 13.7	$ 82.8	$ 48.3