Balance Sheet Components - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross	$ 41,056		$ 41,056		$ 31,866
Accumulated Amortization	(13,316)		(13,316)		(9,510)
Net	27,740		27,740		22,356
Intangible assets, net	27,740		27,740		22,356
Amortization of intangible assets	2,100	$ 1,400	3,805	$ 2,753
Developed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	35,988		35,988		30,588
Accumulated Amortization	(12,249)		(12,249)		(8,738)
Net	23,739		$ 23,739		21,850
Weighted Average Remaining Useful Life (years)			3 years 4 months 24 days
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	3,918		$ 3,918		0
Accumulated Amortization	(308)		(308)		0
Net	3,610		$ 3,610		0
Weighted Average Remaining Useful Life (years)			6 years 4 months 24 days
Trademarks and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	1,150		$ 1,150		1,278
Accumulated Amortization	(759)		(759)		(772)
Net	$ 391		$ 391		$ 506
Weighted Average Remaining Useful Life (years)			7 months 6 days