Employee Separation and Plant Phaseout Costs (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended		3 Months Ended	9 Months Ended		3 Months Ended			12 Months Ended	21 Months Ended		3 Months Ended			12 Months Ended	21 Months Ended		3 Months Ended			12 Months Ended	21 Months Ended		3 Months Ended			12 Months Ended	21 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Cost of Sales [Member]	Sep. 30, 2013 Cost of Sales [Member]	Sep. 30, 2014 Cost of Sales [Member]	Sep. 30, 2013 Cost of Sales [Member]	Sep. 30, 2014 Selling, General and Administrative Expenses [Member]	Sep. 30, 2013 Selling, General and Administrative Expenses [Member]	Sep. 30, 2014 Selling, General and Administrative Expenses [Member]	Sep. 30, 2013 Selling, General and Administrative Expenses [Member]	Dec. 31, 2013 Facility Closing [Member] facility	Dec. 31, 2013 Administrative Office Closing [Member] facility	Sep. 30, 2014 BRAZIL	Sep. 30, 2014 BRAZIL	Sep. 30, 2014 BRAZIL Assets [Member]	Sep. 30, 2014 Spartech [Member]	Jun. 30, 2014 Spartech [Member]	Mar. 31, 2014 Spartech [Member]	Dec. 31, 2013 Spartech [Member]	Sep. 30, 2014 Spartech [Member]	Dec. 31, 2012 Spartech [Member]	Sep. 30, 2014 Spartech [Member] Assets [Member]	Jun. 30, 2014 Spartech [Member] Assets [Member]	Mar. 31, 2014 Spartech [Member] Assets [Member]	Dec. 31, 2013 Spartech [Member] Assets [Member]	Sep. 30, 2014 Spartech [Member] Assets [Member]	Dec. 31, 2012 Spartech [Member] Assets [Member]	Sep. 30, 2014 Spartech [Member] Employee Severance [Member]	Jun. 30, 2014 Spartech [Member] Employee Severance [Member]	Mar. 31, 2014 Spartech [Member] Employee Severance [Member]	Dec. 31, 2013 Spartech [Member] Employee Severance [Member]	Sep. 30, 2014 Spartech [Member] Employee Severance [Member]	Dec. 31, 2012 Spartech [Member] Employee Severance [Member]	Sep. 30, 2014 Spartech [Member] Other Restructuring [Member]	Jun. 30, 2014 Spartech [Member] Other Restructuring [Member]	Mar. 31, 2014 Spartech [Member] Other Restructuring [Member]	Dec. 31, 2013 Spartech [Member] Other Restructuring [Member]	Sep. 30, 2014 Spartech [Member] Other Restructuring [Member]	Dec. 31, 2012 Spartech [Member] Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring And Related Cost, Number Of Facilities Closed													6	1
Severance Costs																$ 3.3
Disposal Group, Not Discontinued Operation, Loss (Gain) on Write-down																5.3
Other Restructuring Costs																1.5
Payments for Restructuring																		(9.2)	(13.0)	(8.9)	(15.4)			0	0	0	0			(5.1)	(4.5)	(3.4)	(6.0)			(4.1)	(8.5)	(5.5)	(9.4)
Restructuring Reserve, Settled without Cash																		(5.0)	(8.9)	(7.7)	(13.6)			(5.0)	(8.9)	(7.7)	(13.6)			0	0	0	0			0	0	0	0
Restructuring Charges	17.9	10.9	70.9	23.7	7.8	4.8	40.9	4.8	10.1	6.1	30.0	18.9			2.9	17.2	5.3	10.2	19.6	15.8	44.1	89.7		5.0	8.9	7.7	13.6	35.2		1.1	2.2	2.6	21.1	27.0		4.1	8.5	5.5	9.4	27.5
Impairment of Intangible Assets (Excluding Goodwill)																1.8
Restructuring and Related Cost, Incurred Cost	4.8		8.1
Restructuring Reserve																		$ 8.0	$ 12.0	$ 14.3	$ 15.1	$ 8.0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 8.0	$ 12.0	$ 14.3	$ 15.1	$ 8.0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0