Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 27, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 130,132	$ 128,790
Less: accumulated depreciation and amortization	(111,231)	(106,469)
Property and Equipment, Net	18,901	22,321
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	75,321	75,094
Capitalized Software [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	33,760	32,696
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	15,050	14,951
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 6,001	$ 6,049

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

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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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