Balance Sheet Components - Prepaid Expenses And Other Current Assets (Details) - USD ($) $ in Thousands		Sep. 27, 2019	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred cost of revenue		$ 9,290	$ 3,671
Prepaid expenses		7,595	4,834
French R&D tax credits receivable(1)	[1]	7,172	7,305
Contract assets(2)	[2]	6,774	3,834
Capitalized sales commissions		1,378	1,098
Other		8,108	2,538
Prepaid Expense and Other Assets, Current		$ 40,317	$ 23,280

[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 September 27, 2019 were approximately $22.3 million and are expected to be recoverable from 2020 through 2023.

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