Customer Financing (Details)	12 Months Ended
	Apr. 24, 2021 USD ($) contract	Apr. 25, 2020 USD ($)	Apr. 27, 2019 USD ($)
Customer Financing [Line Items]
Maximum credit financed for equipment purchases for any one customer	$ 1,000,000
Number of customer financing contracts | contract	2
Financing contracts sold	$ 369,497,000	$ 357,616,000	$ 279,204,000
Net sales from sales of financing contracts	(2,048,000)	43,919,000	16,883,000
Proceeds from receivables sold	401,535,000	346,077,000	$ 369,588,000
Cash and cash equivalents	143,244,000	77,944,000
Current receivables of finance contracts not yet sold	50,638,000	21,391,000
Finance contracts receivable sold and outstanding	$ 646,503,000
Maximum bad debt write-offs (percentage)	1.00%
Unsettled Financing Arrangements
Customer Financing [Line Items]
Cash and cash equivalents	$ 36,771,000	$ 21,830,000
The Bank of Tokyo-Mitsubishi UFJ, Ltd.
Customer Financing [Line Items]
Percentage of principal amount of financing contracts held as collateral (at least)	15.00%
Capacity under agreement	$ 525,000,000
Fifth Third Bank
Customer Financing [Line Items]
Percentage of principal amount of financing contracts held as collateral (at least)	15.00%
Capacity under agreement	$ 100,000,000