Inventories (Detail) - USD ($) $ in Thousands	Jun. 26, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 54,720	$ 35,612
Work in process	172,678	177,780
Finished goods	30,304	25,506
Subtotal	257,702	238,898
Less: LIFO reserve balance	47,855	48,508
Inventories	$ 209,847	$ 190,390

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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 by which inventory stated at last-in first-out (LIFO) is less than (in excess of) inventory stated at other inventory cost methods.

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

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

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