Inventories - Summary of Inventories (Details) - USD ($) $ in Thousands	Apr. 26, 2020	Jan. 26, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 2,260	$ 2,223
Work in progress	53,692	50,640
Finished goods	20,981	20,147
Inventories	$ 76,933	$ 73,010

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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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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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