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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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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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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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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Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019	Dec. 28, 2019
Property, Plant and Equipment
Accumulated depreciation and amortization	$ (463,163)		$ (463,163)		$ (419,915)
Total	339,870		339,870		344,617
Depreciation	14,200	$ 13,300	41,953	$ 38,988
Land
Property, Plant and Equipment
Property, plant, and equipment, gross	23,438		23,438		24,758
Building
Property, Plant and Equipment
Property, plant, and equipment, gross	122,914		122,914		108,501
Equipment
Property, Plant and Equipment
Property, plant, and equipment, gross	$ 656,681		$ 656,681		$ 631,273