INTANGIBLE ASSETS (Details) $ in Thousands	6 Months Ended
	Jul. 01, 2017 USD ($) item	Dec. 31, 2016 USD ($)
Intangible assets
Intangible assets, gross	$ 24,413	$ 24,413
Less: Accumulated amortization	(9,984)	(9,600)
Intangible assets, net	14,429	14,813
Intangibles not subject to amortization	$ 8,400	8,400
Minimum
Intangible assets
Amortization period of intangible assets	5 years
Maximum
Intangible assets
Amortization period of intangible assets	20 years
Patents and licenses
Intangible assets
Intangible assets, gross	$ 3,766	3,766
Customer relationships
Intangible assets
Intangible assets, gross	6,946	6,946
Other intangibles
Intangible assets
Intangible assets, gross	1,882	1,882
Brand names
Intangible assets
Intangible assets, gross	$ 11,819	$ 11,819
Number of indefinite-lived intangible assets | item	1