Business Segment and Geographic Information (Information About Reportable Segments) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information [Line Items]
Net sales	$ 136,231	$ 142,820	$ 132,452	$ 125,979	$ 124,176	$ 129,134	$ 125,296	$ 120,155	$ 537,482	[1]	$ 498,761	[1]	$ 548,341	[1]
Operating income (loss)									49,280		25,664		53,482
Total assets	806,534				760,024				806,534		760,024
Capital expenditures									16,859		23,774		21,316
Depreciation & amortization									26,351		27,130		26,308
Investment in unconsolidated joint ventures	18,463				21,171				18,463		21,171
Equity income in unconsolidated joint ventures									4,326		4,743		5,451
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales									537,482		498,761		548,341
Operating income (loss)									49,280		25,664		53,482
Total assets	806,534				759,278				806,534		759,278		676,785
Capital expenditures									16,859		23,774		21,316
Depreciation & amortization									26,351		27,130		26,308
Investment in unconsolidated joint ventures	18,463				21,171				18,463		21,171		23,868
Equity income in unconsolidated joint ventures									4,326		4,743		5,451
Operating Segments [Member] | High Performance Foams [Member] | Reportable Segment [Member]
Segment Reporting Information [Line Items]
Net sales									168,082		179,421		177,645
Operating income (loss)									22,339		25,730		28,280
Total assets	221,848				233,401				221,848		233,401		192,829
Capital expenditures									3,030		4,947		5,325
Depreciation & amortization									6,410		7,947		7,873
Investment in unconsolidated joint ventures	18,463				21,171				18,463		21,171		23,868
Equity income in unconsolidated joint ventures									4,326		4,743		5,451
Operating Segments [Member] | Printed Circuit Materials [Member] | Reportable Segment [Member]
Segment Reporting Information [Line Items]
Net sales									184,949		161,893		166,424
Operating income (loss)									18,788		8,170		11,127
Total assets	177,716				156,103				177,716		156,103		123,883
Capital expenditures									7,793		12,849		5,901
Depreciation & amortization									7,004		7,172		6,348
Investment in unconsolidated joint ventures
Equity income in unconsolidated joint ventures
Operating Segments [Member] | Power Electronics Solutions [Member] | Reportable Segment [Member]
Segment Reporting Information [Line Items]
Net sales									160,730		134,279		180,234
Operating income (loss)									1,088		(12,022)		11,320
Total assets	382,818				345,013				382,818		345,013		338,418
Capital expenditures									5,287		5,746		9,362
Depreciation & amortization									12,406		11,083		10,989
Investment in unconsolidated joint ventures	0				0				0		0		0
Equity income in unconsolidated joint ventures									0		0		0
Operating Segments [Member] | Other [Member] | Reportable Segment [Member]
Segment Reporting Information [Line Items]
Net sales									23,721		23,168		24,038
Operating income (loss)									7,065		3,786		2,755
Total assets	24,152				24,761				24,152		24,761		21,655
Capital expenditures									749		232		728
Depreciation & amortization									531		928		1,098
Investment in unconsolidated joint ventures
Equity income in unconsolidated joint ventures

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