Plant, Equipment and Timberlands - Summary of Plant, Equipment and Timberlands (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ (569,386)	$ (490,032)
Subtotal	519,919	510,892
Construction in progress	23,330	26,508
Timberlands, less depletion	18	21
Total	543,267	537,421	$ 556,044
Land and Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	173,646	163,066
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	754,737	685,081
Furniture, Fixtures, and Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 160,922	$ 152,777

Property plant and equipment net excluding construction in progress asset retirement obligation timberlands.

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- Definition

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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Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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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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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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Amount before accumulated depreciation and depletion of forest crops and land devoted primarily to the growth and harvest of forest crops for commercial purposes.

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