Segment Information - Information About Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Net sales	$ 132,452	$ 125,295	$ 258,432	$ 245,450
Segment operating income (loss)	8,107	9,017	18,922	8,510
Equity income in unconsolidated joint ventures	762	1,305	1,291	1,962
Other income (expense), net	(177)	261	(766)	121
Net realized investment gain (loss)	0	0	0	(3,245)
Interest income (expense), net	(830)	(1,072)	(1,735)	(2,262)
Income (loss) before income tax expense (benefit)	7,862	9,511	17,712	5,086
Reportable Segment [Member]
Segment Reporting Information [Line Items]
Net sales	132,452	125,295	258,432	245,450
Segment operating income (loss)	8,107	9,017	18,922	8,510
Equity income in unconsolidated joint ventures	762	1,305	1,291	1,962
Other income (expense), net	(177)	261	(766)	121
Net realized investment gain (loss)				(3,245)
Interest income (expense), net	(830)	(1,072)	(1,735)	(2,262)
Income (loss) before income tax expense (benefit)	7,862	9,511	17,712	5,086
Reportable Segment [Member] | High Performance Foams [Member]
Segment Reporting Information [Line Items]
Net sales	39,933	43,329	82,379	83,763
Segment operating income (loss)	3,532	5,708	10,132	7,153
Reportable Segment [Member] | Printed Circuit Materials [Member]
Segment Reporting Information [Line Items]
Net sales	45,584	40,533	89,148	79,914
Segment operating income (loss)	3,996	3,123	7,793	2,777
Reportable Segment [Member] | Power Electronics Solutions [Member] | Curamik Electronics Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	28,508	23,908	51,814	48,200
Segment operating income (loss)	(2,514)	(1,205)	(5,636)	(2,978)
Reportable Segment [Member] | Power Electronics Solutions [Member] | Power Distribution Systems [Member]
Segment Reporting Information [Line Items]
Net sales	12,276	11,573	23,269	22,089
Segment operating income (loss)	1,112	135	2,649	(515)
Reportable Segment [Member] | Other [Member]
Segment Reporting Information [Line Items]
Net sales	6,151	5,952	11,822	11,484
Segment operating income (loss)	$ 1,981	$ 1,256	$ 3,984	$ 2,073