Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Oct. 03, 2017	Sep. 27, 2016	Oct. 03, 2017	Sep. 27, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (8,335)	$ (9,841)	$ (36,995)	$ (26,301)
Other comprehensive (loss) income:
Foreign currency translation adjustments	(11)	(24)	(20)	(103)
Other comprehensive loss	(11)	(24)	(20)	(103)
Comprehensive loss	$ (8,346)	$ (9,865)	$ (37,015)	$ (26,404)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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