Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 24, 2016	Sep. 30, 2017	Sep. 24, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 12,563	$ (14,198)	$ 35,325	$ 8,887
Other comprehensive income, net of tax:
Foreign currency translation adjustments	1,540	989	5,769	2,508
Unrealized gains (losses) on available-for-sale marketable securities	(15)	17	(38)	58
Unrealized gains (losses) on derivative instruments	(36)	(233)	4	(233)
Other comprehensive income, net of tax	1,489	773	5,735	2,333
Comprehensive income (loss)	$ 14,052	$ (13,425)	$ 41,060	$ 11,220

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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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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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities.

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