Segment Information (Income by Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Net sales	$ 206,783	$ 165,259	$ 612,035	$ 483,314
Operating income	39,587	23,146	111,788	66,002
Equity income in unconsolidated joint ventures	1,384	898	3,359	2,220
Other income (expense), net	1,596	676	2,126	320
Interest expense, net	(1,639)	(811)	(4,834)	(3,047)
Income before income tax expense	40,928	23,909	112,439	65,495
Advanced Connectivity Solutions
Segment Reporting Information [Line Items]
Net sales	72,713	65,518	225,595	206,115
Operating income	14,465	7,605	47,362	34,334
Elastomeric Material Solutions
Segment Reporting Information [Line Items]
Net sales	82,239	54,391	236,673	146,476
Operating income	17,846	10,932	44,826	21,584
Power Electronics Solutions
Segment Reporting Information [Line Items]
Net sales	46,409	39,777	132,966	113,391
Operating income	5,429	2,767	14,024	4,540
Other
Segment Reporting Information [Line Items]
Net sales	5,422	5,573	16,801	17,332
Operating income	$ 1,847	$ 1,842	$ 5,576	$ 5,544