Segment Information (Information About Reportable Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 146,640	$ 125,979
Operating income (loss)	21,457	10,814
Equity income in unconsolidated joint ventures	977	529
Other income (expense), net	(1,191)	(589)
Interest income (expense), net	(748)	(905)
Income (loss) before income tax expense (benefit)	20,495	9,849
Reportable Segment [Member]
Segment Reporting Information [Line Items]
Net sales	146,640	125,979
Operating income (loss)	21,457	10,814
Equity income in unconsolidated joint ventures	977	529
Other income (expense), net	(1,191)	(589)
Interest income (expense), net	(748)	(905)
Income (loss) before income tax expense (benefit)	20,495	9,849
Reportable Segment [Member] | Printed Circuit Materials [Member]
Segment Reporting Information [Line Items]
Net sales	58,536	43,565
Operating income (loss)	11,960	3,796
Reportable Segment [Member] | High Performance Foams [Member]
Segment Reporting Information [Line Items]
Net sales	41,204	42,446
Operating income (loss)	5,729	6,599
Reportable Segment [Member] | Power Electronics Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	40,798	34,297
Operating income (loss)	1,565	(1,585)
Reportable Segment [Member] | Other [Member]
Segment Reporting Information [Line Items]
Net sales	6,102	5,671
Operating income (loss)	$ 2,203	$ 2,004