Segment Information (Income by Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Net sales	$ 157,489	$ 163,098	$ 318,056	$ 328,149
Operating income	18,756	20,582	42,856	40,752
Equity income in unconsolidated joint ventures	708	392	1,321	1,311
Other income (expense), net	191	(517)	(356)	(646)
Interest expense, net	(1,115)	(1,304)	(2,236)	(2,310)
Income before income tax expense	18,540	19,153	41,585	39,107
Advanced Connectivity Solutions
Segment Reporting Information [Line Items]
Net sales	67,222	66,408	140,598	137,695
Operating income	10,829	12,076	26,729	24,944
Elastomeric Material Solutions
Segment Reporting Information [Line Items]
Net sales	45,767	47,016	92,084	91,572
Operating income	5,348	5,548	10,653	8,581
Power Electronics Solutions
Segment Reporting Information [Line Items]
Net sales	38,363	38,539	73,614	77,068
Operating income	477	877	1,773	3,268
Other
Segment Reporting Information [Line Items]
Net sales	6,137	11,135	11,760	21,814
Operating income	$ 2,102	$ 2,081	$ 3,701	$ 3,959