Balance Sheet Components - Total Cash, Cash Equivalents And Restricted Cash (Details) - USD ($) $ in Thousands		Mar. 30, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		$ 52,045	$ 57,024
Restricted cash included in prepaid expenses and other current assets(1)	[1]	285	530
Restricted cash included in other long-term assets(2)	[2]		1,203
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 52,330	$ 58,757	$ 57,130	$ 57,420

[1] 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 These restricted funds are invested in bank deposits and cannot be withdrawn from the Company’s accounts without the prior written consent of the applicable secured party.

[2] As of December 31, 2017, the Company had approximately $1.2 million of restricted cash for the bank guarantee associated with the TVN French Subsidiary’s office building lease. The restriction was released and accordingly, the amount was reclassified to “Cash and cash equivalents” in the three months ended March 30, 2018.