Gains on Dispositions of Plant, Equipment and Timberlands (Summary for Sale of Timberlands and Other Assets) (Detail) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018 USD ($) a	Sep. 30, 2017 USD ($) a	Sep. 30, 2018 USD ($) a	Sep. 30, 2017 USD ($) a
Property, Plant and Equipment [Line Items]
Proceeds			$ 2,073	$ 209
Gain (loss)	$ 249	$ 93	$ 1,939	$ 168
Timberlands [Member]
Property, Plant and Equipment [Line Items]
Acres \| a	1,103	332	1,103	332
Proceeds			$ 2,046	$ 209
Gain (loss)			1,929	188
Other [Member]
Property, Plant and Equipment [Line Items]
Proceeds			27
Gain (loss)			$ 10	$ (20)

Area of land held.

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- Definition

Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

+ Details

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- Definition

The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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