Balance Sheet Components Additional Information (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 28, 2019	Dec. 31, 2018
French R&D tax credits receivable, noncurrent	[1]	$ 21,830	$ 19,249
TVN [Member] | Research Tax Credit Carryforward [Member]
The number of years R&D tax credits can be used to offset against income tax payable after incurred		4 years
Other Noncurrent Assets [Member] | TVN [Member] | Research Tax Credit Carryforward [Member]
French R&D tax credits receivable, noncurrent		$ 21,800

[1] The Company’s TVN subsidiary in France (the “TVN French Subsidiary”) participates in the French Crédit d’Impôt Recherche program (the “R&D tax credits”) which allows companies to monetize eligible research expenses. The R&D tax credits can be used to offset against income tax payable to the French government in each of the four years after being incurred, or if not utilized, are recoverable in cash. The amount of R&D tax credits recoverable are subject to audit by the French government. The R&D tax credits receivable at June 28, 2019 were approximately $21.8 million and are expected to be recoverable from 2020 through 2023.