Balance Sheet Information - Equipment and Leasehold Improvements, Net (Detail) - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 29, 2017
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ (40,994)	$ (38,879)
Equipment and leasehold improvements net excluding construction in progress	18,679	18,731
Construction in progress	20,090	13,515
Total	38,769	32,246
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross	11,853	11,672
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross	3,355	3,318
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross	20,459	19,781
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross	$ 24,006	$ 22,839

Property plant and equipment net excluding construction in progress.

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- Definition

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 of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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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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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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