Balance Sheet Information - Equipment and Leasehold Improvements, Net (Detail) - USD ($) $ in Thousands	Dec. 29, 2017	Dec. 20, 2017	Dec. 30, 2016
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements net excluding construction in progress		$ 57,956	$ 48,107
Accumulated depreciation		(38,879)	(33,825)
Construction in progress		13,515	4,576
Total	$ 32,246	32,592	18,858
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		11,672	11,135
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		3,318	3,118
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		19,781	17,016
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		$ 23,185	$ 16,838

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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