Schedule of Inventories Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Inventory Disclosure [Abstract]
Finished products	$ 563,315	$ 552,999	$ 495,793
Products in process and raw materials	62,857	62,761	61,815
Supplies and expendable parts	128,754	128,792	120,054
Inventories, Gross	754,926	744,552	677,662
Less: Allowances	(148,132)	(143,961)	(140,662)
Total	$ 606,794	$ 600,591	$ 537,000

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of valuation reserve for inventory.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The aggregate carrying amount as of the balance sheet date of items held by the entity which are partially completed at the time of measurement and unprocessed items that will go through the production process and become part of the final product. Includes supplies used directly or indirectly in the manufacturing or production process. This element may be used when the reporting entity combines work in process and raw materials into an aggregate amount.

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Amount before valuation and LIFO reserves of other supplies used within the manufacturing or production process expected to be consumed within one year or operating cycle, if longer.

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