Segment Information (Income by Reportable Segments) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Net sales	[1]	$ 160,366	$ 163,052	$ 488,515	$ 463,187
Operating income		23,055	28,389	63,665	66,066
Equity income in unconsolidated joint ventures		877	953	2,187	2,992
Other income (expense), net		(756)	(107)	(1,404)	(1,374)
Interest expense, net		(1,126)	(698)	(3,435)	(2,167)
Income before income tax expense (benefit)		22,050	28,537	61,013	65,517
Advanced Connectivity Solutions [Member]
Segment Reporting Information [Line Items]
Net sales		66,160	63,353	203,855	183,397
Operating income		11,949	14,095	36,831	36,355
Elastomeric Material Solutions [Member]
Segment Reporting Information [Line Items]
Net sales		46,783	46,709	138,355	130,709
Operating income		8,116	8,442	16,661	18,752
Power Electronics Solutions [Member]
Segment Reporting Information [Line Items]
Net sales		36,565	46,468	113,633	130,185
Operating income		1,057	3,683	4,279	4,515
Other [Member]
Segment Reporting Information [Line Items]
Net sales		10,858	6,522	32,672	18,896
Operating income		1,933	2,169	5,894	6,444
United States [Member]
Segment Reporting Information [Line Items]
Net sales	[1]	40,630	34,714	126,825	98,353
China [Member]
Segment Reporting Information [Line Items]
Net sales	[1]	55,233	67,032	172,405	179,158
Germany [Member]
Segment Reporting Information [Line Items]
Net sales	[1]	21,942	23,793	60,361	72,351
Other [Member]
Segment Reporting Information [Line Items]
Net sales	[1]	$ 42,561	$ 37,513	$ 128,924	$ 113,325

[1] Net sales were allocated to countries based on the location of the customer.