Segment Information (Income by Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Net sales	$ 201,424	$ 157,489	$ 405,252	$ 318,056
Operating income	32,759	18,756	72,200	42,856
Equity income in unconsolidated joint ventures	966	708	1,976	1,321
Other income (expense), net	(185)	191	530	(356)
Interest expense, net	(1,947)	(1,115)	(3,195)	(2,236)
Income before income tax expense	31,593	18,540	71,511	41,585
Advanced Connectivity Solutions
Segment Reporting Information [Line Items]
Net sales	74,340	67,222	152,882	140,598
Operating income	13,208	10,829	32,897	26,729
Elastomeric Material Solutions
Segment Reporting Information [Line Items]
Net sales	77,585	45,767	154,434	92,084
Operating income	14,068	5,348	26,980	10,653
Power Electronics Solutions
Segment Reporting Information [Line Items]
Net sales	43,905	38,363	86,557	73,614
Operating income	3,660	477	8,595	1,773
Other
Segment Reporting Information [Line Items]
Net sales	5,594	6,137	11,379	11,760
Operating income	$ 1,823	$ 2,102	$ 3,728	$ 3,701