Balance Sheet Components Property and equipment (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Apr. 01, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Depreciation, Depletion and Amortization	$ 1,600	$ 5,300
Machinery and Equipment, Gross	22,177	20,611
Furniture and Fixtures, Gross	645	654
Leasehold Improvements, Gross	3,895	3,367
Capitalized Computer Software, Gross	2,580	2,519
Property, Plant and Equipment, Gross	29,297	27,151
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(16,849)	(15,342)
Property and equipment, net	$ 12,448	$ 11,809

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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- Definition

Amount before accumulated amortization of capitalized costs for computer software, including but not limited to, acquired and internally developed computer software.

+ References

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- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

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- Definition

Amount before accumulated depreciation of equipment commonly used in offices and stores that have no permanent connection to the structure of a building or utilities. Examples include, but are not limited to, desks, chairs, tables, and bookcases.

+ References

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- Definition

Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.

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- Definition

Amount before accumulated depreciation of tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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