Balance Sheet Components - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross	$ 41,056		$ 41,056		$ 41,056
Accumulated Amortization	(23,537)		(23,537)		(17,436)
Net	17,519		17,519		23,620
Amortization of intangible assets	2,000	$ 2,100	6,100	$ 5,866
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross	35,988		35,988		35,988
Accumulated Amortization	(21,506)		(21,506)		(15,983)
Net	14,482		14,482		20,005
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross	3,790		3,790		3,790
Accumulated Amortization	(857)		(857)		(451)
Net	2,933		2,933		3,339
Trademarks and other
Finite-Lived Intangible Assets [Line Items]
Gross	1,278		1,278		1,278
Accumulated Amortization	(1,174)		(1,174)		(1,002)
Net	$ 104		$ 104		$ 276