Balance Sheet Components - Prepaid Expenses And Other Current Assets (Details) - USD ($) $ in Thousands		Mar. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred cost of revenue		$ 7,149	$ 4,440
French R&D tax credits receivable(1)	[1]	6,747	6,609
Prepaid maintenance, royalty, rent, property taxes and value added tax		5,646	3,867
Contract assets(2)	[2]	4,984
Restricted Cash	[3]	285	530
Other		5,156	3,485
Prepaid Expense and Other Assets, Current		$ 29,967	$ 18,931

[1] The Company’s acquired TVN subsidiary in France (the “TVN French Subsidiary”) which participates in the French Crédit d’Impôt Recherche (“CIR”) 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 March 30, 2018 were approximately $30.6 million and are expected to be recoverable from 2018 through 2021 with $6.7 million reported under “Prepaid expenses and other current assets” and $23.9 million reported under “Other long-term assets” on the Company’s Condensed Consolidated Balance Sheets.

[2] Contract assets reflect the satisfied performance obligations which not yet have an unconditional right to consideration.

[3] Amounts represent cash collateral security for certain bank guarantees. These restricted funds are invested in bank deposits and cannot be withdrawn from the Company’s accounts without the prior written consent of the applicable secured party.