Condensed Consolidating Financial Statements (Statements of Operations and Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Condensed Consolidating Statements of Operations
Net sales	$ 1,099.1	$ 1,175.4	$ 1,889.4	$ 2,010.2
Cost of goods sold	767.0	813.8	1,355.8	1,425.5
Gross profit	332.1	361.6	533.6	584.7
Operating Expenses:
Selling, general and administrative expenses	152.4	161.4	298.2	316.6
Losses (gains) and other expenses, net	2.1	0.2	3.2	7.5
Restructuring charges	(0.1)	0.5	0.4	1.3
Gain (Loss) on Disposition of Business and Related Property	(0.4)	22.1	(8.8)	11.8
Gain (Loss) on Disposition of Assets	0.0	31.4	0.0	31.4
Insurance proceeds for lost profits	(26.0)	0.0	(65.5)	0.0
Loss(gain) from natural disaster, net of Insurance recoveries	(5.9)	0.0	(12.8)	0.0
Income from equity method investments	(4.6)	(4.9)	(7.2)	(8.4)
Operating income	213.8	195.1	308.5	248.1
non-cash pension settlement loss	60.6	0.0	60.6	0.0
Interest expense, net	13.1	9.8	23.9	18.2
Other (income) expense, net	0.3	0.8	1.2	1.4
Income from continuing operations before income taxes	139.8	184.5	222.8	228.5
Income tax benefit	28.8	45.3	42.4	51.4
Income from continuing operations	111.0	139.2	180.4	177.1
Loss from discontinued operations	(0.3)	(1.6)	(0.4)	(1.6)
Net income	110.7	137.6	180.0	175.5
Other comprehensive income (loss), net of tax	50.6	0.3	59.2	(23.6)
Comprehensive income	161.3	137.9	239.2	151.9
Eliminations [Member]
Condensed Consolidating Statements of Operations
Net sales	(66.6)	(186.2)	(120.4)	(346.7)
Cost of goods sold	(126.2)	(186.5)	(119.3)	(344.7)
Gross profit	59.6	0.3	(1.1)	(2.0)
Operating Expenses:
Selling, general and administrative expenses	0.3	(0.3)	0.0	(0.5)
Losses (gains) and other expenses, net	(0.2)	(0.1)	(0.2)	(0.2)
Restructuring charges	0.0	0.0	0.0	0.0
Gain (Loss) on Disposition of Business and Related Property	0.0	0.0	0.0	0.0
Gain (Loss) on Disposition of Assets		0.0		0.0
Insurance proceeds for lost profits	0.0		0.0
Loss(gain) from natural disaster, net of Insurance recoveries	0.0		0.0
Income from equity method investments	87.7	155.5	198.9	200.3
Operating income	(28.2)	(154.8)	(199.8)	(201.6)
non-cash pension settlement loss	0.0		0.0
Interest expense, net	0.0	0.0	0.0	0.0
Other (income) expense, net	0.0	0.0	0.0	0.0
Income from continuing operations before income taxes	(28.2)	(154.8)	(199.8)	(201.6)
Income tax benefit	0.0	(0.1)	(0.3)	0.2
Income from continuing operations	(28.2)	(154.7)	(199.5)	(201.8)
Loss from discontinued operations	0.0	0.0	0.0	0.0
Net income	(28.2)	(154.7)	(199.5)	(201.8)
Other comprehensive income (loss), net of tax	0.0	0.0	0.0	0.0
Comprehensive income	(28.2)	(154.7)	(199.5)	(201.8)
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 (gains) and other expenses, net	0.2	0.3	(0.4)	1.4
Restructuring charges	0.0	0.0	0.0	0.0
Gain (Loss) on Disposition of Business and Related Property	0.0	0.0	0.0	0.0
Gain (Loss) on Disposition of Assets		0.0		0.0
Insurance proceeds for lost profits	0.0		0.0
Loss(gain) from natural disaster, net of Insurance recoveries	0.0		0.0
Income from equity method investments	(112.5)	(139.6)	(183.2)	(180.2)
Operating income	112.3	139.3	183.6	178.8
non-cash pension settlement loss	0.0		0.0
Interest expense, net	2.2	2.4	4.6	4.8
Other (income) expense, net	0.0	0.0	0.0	0.0
Income from continuing operations before income taxes	110.1	136.9	179.0	174.0
Income tax benefit	(0.6)	(0.7)	(1.0)	(1.5)
Income from continuing operations	110.7	137.6	180.0	175.5
Loss from discontinued operations	0.0	0.0	0.0	0.0
Net income	110.7	137.6	180.0	175.5
Other comprehensive income (loss), net of tax	(2.0)	(2.3)	4.4	(9.4)
Comprehensive income	108.7	135.3	184.4	166.1
Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Operations
Net sales	1,019.2	1,057.8	1,742.1	1,774.1
Cost of goods sold	723.6	745.0	1,254.4	1,278.3
Gross profit	295.6	312.8	487.7	495.8
Operating Expenses:
Selling, general and administrative expenses	147.1	151.0	283.6	284.7
Losses (gains) and other expenses, net	1.3	(3.3)	2.8	0.7
Restructuring charges	(0.1)	0.0	0.2	0.7
Gain (Loss) on Disposition of Business and Related Property	(0.3)	0.9	(1.2)	0.9
Gain (Loss) on Disposition of Assets		0.0		0.0
Insurance proceeds for lost profits	(26.0)		(65.5)
Loss(gain) from natural disaster, net of Insurance recoveries	(5.9)		(12.8)
Income from equity method investments	24.0	(17.1)	(17.1)	(21.7)
Operating income	154.9	183.1	295.3	232.3
non-cash pension settlement loss	60.6		60.6
Interest expense, net	9.3	5.2	15.4	9.3
Other (income) expense, net	6.8	0.7	1.0	1.4
Income from continuing operations before income taxes	78.2	177.2	218.3	221.6
Income tax benefit	23.5	43.8	33.6	49.2
Income from continuing operations	54.7	133.4	184.7	172.4
Loss from discontinued operations	0.0	0.0	0.0	0.0
Net income	54.7	133.4	184.7	172.4
Other comprehensive income (loss), net of tax	50.0	11.9	50.4	(8.8)
Comprehensive income	104.7	145.3	235.1	163.6
Non-Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Operations
Net sales	146.5	303.8	267.7	582.8
Cost of goods sold	169.6	255.3	220.7	491.9
Gross profit	(23.1)	48.5	47.0	90.9
Operating Expenses:
Selling, general and administrative expenses	5.0	10.7	14.6	32.4
Losses (gains) and other expenses, net	0.8	3.3	1.0	5.6
Restructuring charges	0.0	0.5	0.2	0.6
Gain (Loss) on Disposition of Business and Related Property	(0.1)	21.2	(7.6)	10.9
Gain (Loss) on Disposition of Assets		31.4		31.4
Insurance proceeds for lost profits	0.0		0.0
Loss(gain) from natural disaster, net of Insurance recoveries	0.0		0.0
Income from equity method investments	(3.8)	(3.7)	(5.8)	(6.8)
Operating income	(25.2)	27.5	29.4	38.6
non-cash pension settlement loss	0.0		0.0
Interest expense, net	1.6	2.2	3.9	4.1
Other (income) expense, net	(6.5)	0.1	0.2	0.0
Income from continuing operations before income taxes	(20.3)	25.2	25.3	34.5
Income tax benefit	5.9	2.3	10.1	3.5
Income from continuing operations	(26.2)	22.9	15.2	31.0
Loss from discontinued operations	(0.3)	(1.6)	0.4	(1.6)
Net income	(26.5)	21.3	14.8	29.4
Other comprehensive income (loss), net of tax	2.6	(9.3)	4.4	(5.4)
Comprehensive income	$ (23.9)	$ 12.0	$ 19.2	$ 24.0