Balance Sheet Components - Restructuring (Details) - Employee Severance [Member] $ in Thousands	3 Months Ended	6 Months Ended
Jul. 01, 2017 USD ($)	Jul. 02, 2016 USD ($)	Jul. 01, 2017 USD ($) employee	Jul. 02, 2016 USD ($)
Restructuring Cost and Reserve [Line Items]
Expected number of positions eliminated \| employee			110
Number of positions eliminated in the period, percent			6.00%
Severance costs			$ 6,400
Restructuring Reserve [Roll Forward]
Beginning balance	$ 2,352	$ 0	0	$ 0
Restructuring charges	0	0	6,375	0
Cash paid	(1,330)	0	(4,625)	0
Other - noncash	0	0	(728)	0
Restructuring Reserve	$ 1,022	$ 0	$ 1,022	$ 0

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Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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The number of positions eliminated during the period as a result of restructuring activities.

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The number of positions eliminated during the period as a percentage of total positions eliminated during the period in connection with the restructuring plan(s).

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of decrease in the reserve for full or partial settlement through consideration other than cash.

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Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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