Balance Sheet Components - Other Long Term Assets (Details) - USD ($) $ in Thousands		Jun. 28, 2019	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
French R&D tax credits receivable(2)	[1]	$ 21,830	$ 19,249
Deferred tax assets		8,932	8,695
Equity investment		3,593	3,593
Other		8,190	6,840
Other Assets, Noncurrent		$ 42,545	$ 38,377

[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.