Commitments and Contingencies - Additional Information (Detail) $ in Thousands	6 Months Ended
Jun. 30, 2016 USD ($) a	Dec. 31, 2015 USD ($)
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Area for which certificate of completion received \| a	288
Portion of site for which certificate not received \| a	80
Accrual for environmental loss contingencies	$ 117
Cost to complete remediation activities	651
Asset retirement obligation	486	$ 1,758
Restructuring charges	2,868
One-time Termination Benefits \| Real estate
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Restructuring charges	1,422
One-time Termination Benefits \| Other natural resources
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Restructuring charges	164
General and Administrative Expense \| One-time Termination Benefits
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Restructuring charges	486
Other Liabilities
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Asset retirement obligation	$ 386	$ 1,667

Acres for which certificate of completion received.

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Portion of site for which certificate not received.

+ References

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The Increase or Decrease in the accrual for environmental loss in the period from revisions in estimates to existing obligations. The amount does not relate to changes in the environmental accrual related to business acquisitions or divestitures, or to currency movements.

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The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6505190

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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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Carrying amount as of the balance sheet date of the liability for remediation, site restoration, postclosure, monitoring commitments, or other exit costs associated with the sale, disposal or abandonment of a particular property resulting from unanticipated contamination of the assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section S99
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-Subparagraph (SAB TOPIC 5.Y.Q4)
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-Name Staff Accounting Bulletin (SAB)
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-Section Y
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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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