Balance Sheet Components - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross	$ 41,056		$ 41,056		$ 31,866
Accumulated Amortization	(15,376)		(15,376)		(9,510)
Net	25,680		25,680		22,356
Amortization of intangible assets	2,100	$ 1,400	5,866	$ 4,134
Developed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	35,988		35,988		30,588
Accumulated Amortization	(14,116)		(14,116)		(8,738)
Net	21,872		21,872		21,850
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	3,790		3,790		0
Accumulated Amortization	(316)		(316)		0
Net	3,474		3,474		0
Trademarks and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	1,278		1,278		1,278
Accumulated Amortization	(944)		(944)		(772)
Net	$ 334		$ 334		$ 506