Operating Segments and Geographic Information (Revenue by Country) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Net sales	$ 222,942	$ 226,863	$ 214,675	$ 214,611	$ 209,008	$ 206,783	$ 201,424	$ 203,828	$ 879,091	$ 821,043	$ 656,314
Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									294,154	301,092	277,787
Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									341,364	312,661	203,181
Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									223,338	184,954	152,367
Other
Disaggregation of Revenue [Line Items]
Net sales									20,235	22,336	22,979
United States
Disaggregation of Revenue [Line Items]
Net sales									246,797	225,398	139,237
United States | Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									52,661	48,277	46,951
United States | Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									152,284	141,508	61,188
United States | Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									37,325	30,403	25,599
United States | Other
Disaggregation of Revenue [Line Items]
Net sales									4,527	5,210	5,499
Other Americas
Disaggregation of Revenue [Line Items]
Net sales									19,261	14,507	10,925
Other Americas | Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									3,104	2,946	2,035
Other Americas | Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									14,453	9,709	7,722
Other Americas | Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									931	1,153	313
Other Americas | Other
Disaggregation of Revenue [Line Items]
Net sales									773	699	855
Total Americas
Disaggregation of Revenue [Line Items]
Net sales									266,058	239,905	150,162
Total Americas | Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									55,765	51,223	48,986
Total Americas | Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									166,737	151,217	68,910
Total Americas | Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									38,256	31,556	25,912
Total Americas | Other
Disaggregation of Revenue [Line Items]
Net sales									5,300	5,909	6,354
China
Disaggregation of Revenue [Line Items]
Net sales									282,091	273,391	241,203
China | Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									136,315	143,065	137,695
China | Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									101,036	93,039	77,033
China | Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									39,781	32,164	20,964
China | Other
Disaggregation of Revenue [Line Items]
Net sales									4,959	5,123	5,511
Other APAC
Disaggregation of Revenue [Line Items]
Net sales									135,412	125,576	103,840
Other APAC | Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									63,318	64,077	53,082
Other APAC | Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									40,788	36,233	29,109
Other APAC | Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									28,414	21,845	17,751
Other APAC | Other
Disaggregation of Revenue [Line Items]
Net sales									2,892	3,421	3,898
Total APAC
Disaggregation of Revenue [Line Items]
Net sales									417,503	398,967	345,043
Total APAC | Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									199,633	207,142	190,777
Total APAC | Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									141,824	129,272	106,142
Total APAC | Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									68,195	54,009	38,715
Total APAC | Other
Disaggregation of Revenue [Line Items]
Net sales									7,851	8,544	9,409
Germany
Disaggregation of Revenue [Line Items]
Net sales									91,015	88,606	81,738
Germany | Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									18,165	23,925	19,842
Germany | Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									9,907	9,211	7,621
Germany | Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									62,359	54,813	53,426
Germany | Other
Disaggregation of Revenue [Line Items]
Net sales									584	657	849
Other EMEA
Disaggregation of Revenue [Line Items]
Net sales									104,515	93,565	79,371
Other EMEA | Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									20,591	18,802	18,182
Other EMEA | Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									22,896	22,961	20,508
Other EMEA | Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									54,528	44,576	34,314
Other EMEA | Other
Disaggregation of Revenue [Line Items]
Net sales									6,500	7,226	6,367
Total EMEA
Disaggregation of Revenue [Line Items]
Net sales									195,530	182,171	161,109
Total EMEA | Advanced Connectivity Solutions
Disaggregation of Revenue [Line Items]
Net sales									38,756	42,727	38,024
Total EMEA | Elastomeric Material Solutions
Disaggregation of Revenue [Line Items]
Net sales									32,803	32,172	28,129
Total EMEA | Power Electronics Solutions
Disaggregation of Revenue [Line Items]
Net sales									116,887	99,389	87,740
Total EMEA | Other
Disaggregation of Revenue [Line Items]
Net sales									$ 7,084	$ 7,883	$ 7,216