The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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The charge against earnings in the period to reduce the carrying amount of real property to fair value.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The cash inflow from the sale of land held for use; excludes sales of land held as inventory or investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
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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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No definition available.

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Property, Plant & Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 28, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant & Equipment [Line Items]
Depreciation and amortization		$ 18,189	$ 17,330	$ 18,904
Loss on impairment of land		912	0	0
Property, Plant and Equipment
Property, Plant & Equipment [Line Items]
Depreciation and amortization		$ 14,800	$ 12,100	$ 12,900
Subsequent Event
Property, Plant & Equipment [Line Items]
Proceeds from sale of excess land	$ 1,000