Restructuring and Impairment Charges (Narrative) (Details) (USD $)	9 Months Ended	3 Months Ended						9 Months Ended				3 Months Ended			9 Months Ended		12 Months Ended	3 Months Ended		6 Months Ended					3 Months Ended			9 Months Ended
	Sep. 30, 2012	Sep. 30, 2013 Employee Severance [Member]	Jun. 30, 2013 Employee Severance [Member]	Sep. 30, 2013 High Performance Foams [Member] Employee Severance [Member]		Sep. 30, 2012 High Performance Foams [Member] Employee Severance [Member]		Sep. 30, 2013 High Performance Foams [Member] Employee Severance [Member]		Sep. 30, 2012 High Performance Foams [Member] Employee Severance [Member]		Sep. 30, 2013 Composite Material Division [Member]	Dec. 31, 2012 Composite Material Division [Member]	Sep. 30, 2012 Composite Material Division [Member]	Sep. 30, 2013 Composite Material Division [Member]	Sep. 30, 2012 Composite Material Division [Member]	Dec. 31, 2011 Composite Material Division [Member]	Sep. 30, 2013 Bremen, Germany [Member] High Performance Foams [Member]	Jun. 30, 2012 Bremen, Germany [Member] High Performance Foams [Member]	Jun. 30, 2012 Bremen, Germany [Member] High Performance Foams [Member]	Jun. 30, 2012 Bremen, Germany [Member] High Performance Foams [Member] Lease Contract Termination [Member]	Jun. 30, 2012 Bremen, Germany [Member] High Performance Foams [Member] Employee Severance [Member]	Jun. 30, 2012 Bremen, Germany [Member] High Performance Foams [Member] Asset Impairments [Member]	Jun. 30, 2012 Bremen, Germany [Member] High Performance Foams [Member] Equipment Removal and Transportation [Member]	Sep. 30, 2013 Pension Benefits [Member]	Jun. 30, 2013 Pension Benefits [Member]	Sep. 30, 2012 Pension Benefits [Member]	Sep. 30, 2013 Pension Benefits [Member]	Sep. 30, 2012 Pension Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Severance and other employee related costs	$ 1,600,000	$ 1,200,000	$ 3,000,000	$ 94,000	[1]	$ 0	[1]	$ 1,345,000	[1]	$ 3,088,000	[1]							$ 1,400,000	$ 1,500,000	$ 3,100,000	$ 900,000	$ 800,000	$ 400,000	$ 300,000
Net sales associated with the discontinued operations												0	5,300,000	1,100,000	200,000	3,700,000	4,800,000
Curtailment charge																										$ 1,537,000		$ 1,537,000

[1] For the nine month period ended September 30, 2013, this includes a pension curtailment charge of $1.5 million. For the nine month period ended September 30, 2012, this includes a net charge of $1.6 million, related to the early retirement program implemented in the first quarter of 2012. See Note 8 - "Pension Benefits and Other Post Retirement Plans" for further information.