Assets (Details 4) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Property, plant and equipment, net
Gross property, plant, and equipment	$ 174,624,000		$ 170,542,000
Less accumulated depreciation and amortization	94,323,000		91,790,000
Net property, plant and equipment	80,301,000		78,752,000
Impairment of tools held in property, plant and equipment	100,000
Depreciation	2,800,000	2,900,000
Goodwill
Impairment of goodwill	0
Goodwill acquired	0
Gross carrying Amount, beginning balance	238,158,000
Accumulated Impairment, beginning balance	123,199,000
Net Amount, beginning balance	114,959,000
Purchase price adjustment	13,000
Gross carrying Amount, ending balance	238,171,000
Accumulated Impairment, ending balance	123,199,000
Net Amount, ending balance	114,972,000
Intangible assets
Impairment of intangible assets	0
Intangible assets acquired	0
Accumulated Amortization and Impairment	131,167,000		123,205,000
Total Gross Intangible Assets	282,513,000		282,513,000
Total Net Intangible Assets	151,346,000		159,308,000
Indefinite-lived trademark
Intangible assets
Indefinite-lived intangible assets	2,900,000		2,900,000
Technology
Intangible assets
Gross Carrying Amount	222,358,000		222,358,000
Accumulated Amortization and Impairment	109,881,000		106,342,000
Net Amount	112,477,000		116,016,000
Customer relationships
Intangible assets
Gross Carrying Amount	47,885,000		47,885,000
Accumulated Amortization and Impairment	16,793,000		14,918,000
Net Amount	31,092,000		32,967,000
Trademarks and tradenames
Intangible assets
Gross Carrying Amount	3,050,000		3,050,000
Accumulated Amortization and Impairment	1,406,000		1,096,000
Net Amount	1,644,000		1,954,000
Other
Intangible assets
Gross Carrying Amount	6,320,000		6,320,000
Accumulated Amortization and Impairment	3,087,000		849,000
Net Amount	3,233,000		5,471,000
Tools
Property, plant and equipment, net
Aggregate selling price	1,300,000	2,300,000
Assets converted and sold	1,300,000	1,400,000
Land
Property, plant and equipment, net
Gross property, plant, and equipment	9,392,000		9,392,000
Building and improvements
Property, plant and equipment, net
Gross property, plant, and equipment	51,984,000		51,979,000
Machinery and equipment
Property, plant and equipment, net
Gross property, plant, and equipment	108,808,000		104,815,000
Leaseholds improvements
Property, plant and equipment, net
Gross property, plant, and equipment	4,440,000		4,356,000
PSP
Goodwill
Net assets acquired	$ 145,500,000