Information About Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Segment Reporting Information [Line Items]
Net sales	$ 126,671	$ 143,501	$ 248,044	$ 279,429
Segment operating income (loss)	9,076	16,507	8,390	29,739
Equity income in unconsolidated joint ventures	1,305	1,323	1,962	2,751
Other income (expense), net	261	280	122	1,629
Net realized investment gain (loss)		29	(3,245)	32
Interest income (expense), net	(1,072)	(1,265)	(2,262)	(2,843)
Income (loss) before income tax expense (benefit)	9,570	16,874	4,967	31,308
Reportable Segment
Segment Reporting Information [Line Items]
Net sales	126,671	143,501	248,044	279,429
Segment operating income (loss)	9,076	16,507	8,390	29,739
Equity income in unconsolidated joint ventures	1,305	1,323	1,962	2,751
Other income (expense), net	261	280	122	1,629
Net realized investment gain (loss)		29	(3,245)	32
Interest income (expense), net	(1,072)	(1,265)	(2,262)	(2,843)
Income (loss) before income tax expense (benefit)	9,570	16,874	4,967	31,308
Reportable Segment | High Performance Foams
Segment Reporting Information [Line Items]
Net sales	43,329	44,021	83,763	83,156
Segment operating income (loss)	5,708	6,658	7,153	11,293
Reportable Segment | Printed Circuit Materials
Segment Reporting Information [Line Items]
Net sales	40,533	43,375	79,914	86,228
Segment operating income (loss)	3,123	4,405	2,777	9,234
Reportable Segment | Power Electronics Solutions | Curamik Electronics Solutions
Segment Reporting Information [Line Items]
Net sales	23,908	34,613	48,200	67,510
Segment operating income (loss)	(1,205)	2,855	(2,978)	3,157
Reportable Segment | Power Electronics Solutions | Power Distribution Systems
Segment Reporting Information [Line Items]
Net sales	11,573	13,978	22,089	26,413
Segment operating income (loss)	135	1,644	(515)	3,909
Reportable Segment | Other
Segment Reporting Information [Line Items]
Net sales	7,328	7,514	14,078	16,122
Segment operating income (loss)	$ 1,315	$ 945	$ 1,953	$ 2,146