Balance Sheet Components - Prepaid Expenses And Other Current Assets (Details) - USD ($) $ in Thousands		Jun. 28, 2019	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred cost of revenue		$ 8,153	$ 3,671
Prepaid expenses		7,998	4,834
Contract assets(1)	[1]	4,163	3,834
Capitalized sales commissions		1,168	1,098
French R&D tax credits receivable		0	7,305
Other		7,727	2,538
Prepaid Expense and Other Assets, Current		$ 29,209	$ 23,280

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