Balance Sheet Components - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross	$ 27,242		$ 27,242		$ 27,370
Accumulated Amortization	(6,414)		(6,414)		(3,789)
Net	20,828		20,828		23,581
Intangible assets, gross	31,182		31,182		31,310
Intangible assets, net	24,768		24,768		27,521
Amortization of intangible assets	1,400	$ 500	2,753	$ 1,066
Developed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	26,092		26,092		26,092
Accumulated Amortization	(5,885)		(5,885)		(3,247)
Net	20,207		$ 20,207		22,845
Weighted Average Remaining Useful Life (years)			4 years 2 months 12 days
Trademarks and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	1,150		$ 1,150		1,278
Accumulated Amortization	(529)		(529)		(542)
Net	621		$ 621		736
Weighted Average Remaining Useful Life (years)			2 years 9 months 18 days
In Process Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 3,940		$ 3,940		$ 3,940

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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Amount before accumulated amortization of intangible assets, excluding goodwill.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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