Inventories (Details) - USD ($) $ in Thousands	Oct. 24, 2020	Apr. 25, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 91,742	$ 92,174
Work in process	17,759	14,064
Finished goods	100,596	96,850
FIFO inventories	210,097	203,088
Excess of FIFO over LIFO	(21,445)	(21,445)
Total inventories	$ 188,652	$ 181,643

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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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