SIGNIFICANT ACCOUNTING POLICIES - Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013
Property, Plant and Equipment
Property, plant and equipment	109,733	$ 100,305	$ 102,564	$ 100,208	$ 98,573	$ 95,717	$ 90,651	$ 85,896
Land [Member]
Property, Plant and Equipment
Property, plant and equipment	3,344				2,693
Buildings and improvements [Member]
Property, Plant and Equipment
Property, plant and equipment	39,489				31,774
Buildings and improvements [Member] | Minimum [Member]
Property, Plant and Equipment
Estimated useful life	15 years
Buildings and improvements [Member] | Maximum [Member]
Property, Plant and Equipment
Estimated useful life	30 years
Manufacturing equipment and tooling [Member]
Property, Plant and Equipment
Property, plant and equipment	40,433				37,844
Manufacturing equipment and tooling [Member] | Minimum [Member]
Property, Plant and Equipment
Estimated useful life	3 years
Manufacturing equipment and tooling [Member] | Maximum [Member]
Property, Plant and Equipment
Estimated useful life	15 years
Furniture, fixtures and computer equipment [Member]
Property, Plant and Equipment
Property, plant and equipment	14,813				14,079
Furniture, fixtures and computer equipment [Member] | Minimum [Member]
Property, Plant and Equipment
Estimated useful life	3 years
Furniture, fixtures and computer equipment [Member] | Maximum [Member]
Property, Plant and Equipment
Estimated useful life	10 years
Other [Member]
Property, Plant and Equipment
Property, plant and equipment	3,425				4,909
Other [Member] | Minimum [Member]
Property, Plant and Equipment
Estimated useful life	3 years
Other [Member] | Maximum [Member]
Property, Plant and Equipment
Estimated useful life	10 years
Construction in process [Member]
Property, Plant and Equipment
Property, plant and equipment	8,229				$ 7,274