CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (26,322)	$ (70,562)	$ (54,099)
Other comprehensive loss:
Unrealized gain (loss) related to marketable securities, net of tax	41	(73)	(172)
Reclassification adjustment for (gains) losses related to marketable securities included in other (expense) income, net	(18)	252	79
Translation adjustment, net of tax	(1,271)	2,620	(1,303)
Change in actuarial valuation of defined benefit pension	369	(95)	150
Comprehensive loss	$ (27,201)	$ (67,858)	$ (55,345)

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 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, attributable to parent entity.

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