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

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.

+ References

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-Publisher FASB
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.13)
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-Publisher SEC
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-Section 02
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Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 25, 2016	Jun. 26, 2015	Jun. 24, 2016	Jun. 26, 2015	Dec. 25, 2015
Property, plant and equipment
Property, plant and equipment, gross			$ 519,482		$ 460,838
Less: Accumulated depreciation			(271,822)		(257,172)
Net property, plant and equipment			247,660		203,666
Depreciation expense	$ 11,500	$ 12,800	23,000	$ 24,700
Land
Property, plant and equipment
Property, plant and equipment, gross			5,021		5,021
Building and land improvements
Property, plant and equipment
Property, plant and equipment, gross			102,194		67,631
Furniture and fixtures
Property, plant and equipment
Property, plant and equipment, gross			27,137		25,332
Computer and office equipment
Property, plant and equipment
Property, plant and equipment, gross			163,214		158,399
Field equipment
Property, plant and equipment
Property, plant and equipment, gross			143,506		138,721
Leasehold improvements
Property, plant and equipment
Property, plant and equipment, gross			$ 78,410		$ 65,734