Balance Sheet Components - Other Long Term Assets (Details) - USD ($) $ in Thousands	Mar. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
R&D tax credits receivable	$ 23,873	$ 22,322
Deferred tax assets	10,462	10,462
Equity investment	3,593	3,593
Others	5,719	6,536
Other Assets, Noncurrent	$ 43,647	$ 42,913