Business Segment and Geographic Information (Information About Reportable Segments) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 173,000	$ 165,259	$ 157,489	$ 160,566	$ 152,928	$ 160,366	$ 163,098	$ 165,051	$ 656,314	[1]	$ 641,443	[1]	$ 610,911	[1]
Operating income									83,852		76,255		81,241
Total assets	1,056,500				930,355				1,056,500		930,355		840,435
Capital expenditures									18,136		24,837		28,755
Depreciation & amortization									37,847		34,054		26,268
Investment in unconsolidated joint ventures	16,183				15,348				16,183		15,348		17,214
Equity income in unconsolidated joint ventures									4,146		2,890		4,123
Advanced Connectivity Solutions
Segment Reporting Information [Line Items]
Net sales									277,787		267,630		240,864
Operating income									43,965		45,115		44,007
Total assets	361,746				315,358				361,746		315,358		217,173
Capital expenditures									7,569		15,532		14,290
Depreciation & amortization									15,654		15,403		9,575
Investment in unconsolidated joint ventures	0								0
Equity income in unconsolidated joint ventures									0
Elastomeric Material Solutions
Segment Reporting Information [Line Items]
Net sales									203,181		180,898		173,671
Operating income									26,593		19,979		23,350
Total assets	421,011				264,982				421,011		264,982		221,013
Capital expenditures									4,051		4,103		6,197
Depreciation & amortization									10,141		9,280		6,561
Investment in unconsolidated joint ventures					15,348						15,348		17,214
Equity income in unconsolidated joint ventures									4,146		2,890		4,123
Power Electronics Solutions
Segment Reporting Information [Line Items]
Net sales									152,367		150,288		171,832
Operating income									5,965		3,750		5,654
Total assets	247,187				320,755				247,187		320,755		377,181
Capital expenditures									6,009		4,185		7,489
Depreciation & amortization									11,208		7,855		9,332
Investment in unconsolidated joint ventures	0				0				0		0		0
Equity income in unconsolidated joint ventures									0		0		0
Other
Segment Reporting Information [Line Items]
Net sales									22,979		42,627		24,544
Operating income									7,329		7,411		8,230
Total assets	26,556				$ 29,260				26,556		29,260		25,068
Capital expenditures									507		1,017		779
Depreciation & amortization									844		$ 1,516		$ 800
Investment in unconsolidated joint ventures	$ 0								0
Equity income in unconsolidated joint ventures									$ 0

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