Note 10 - Stock-based Compensation (Details Textual) - USD ($)	12 Months Ended
	Apr. 29, 2023	Apr. 30, 2022	May 01, 2021
Statement [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)	0	30,000	266,500
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year)		6 years 6 months	7 years 2 months 12 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate		20.74%	19.36%
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate		0.82%	3.85%
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate		2.48%	1.30%
Share-Based Payment Arrangement, Expense	$ 677,000	$ 695,000	$ 462,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value	360,000	1,400,000	1,900,000
Proceeds from Stock Options Exercised	311,000	335,000	491,000
Share-Based Payment Arrangement, Expense, Tax Benefit	67,000	$ 283,000	$ 382,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 2,300,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	5 years 4 months 24 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term (Year)	3 years 1 month 6 days	4 years 2 months 12 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value	$ 16,000,000.0	$ 10,800,000
Omnibus Plan [Member]
Statement [Line Items]
Share Based Compensation Arrangement by Share Based Payment Award Number of Shares Authorized Per Individual (in shares)	3,360,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)	10 years
Omnibus Plan [Member] | Stock Options or Stock Awards [Member]
Statement [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	9,600,000
Omnibus Plan [Member] | SARS Dividend Equivalents and Other Awards [Member]
Statement [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	9,600,000
Special Stock Option Plan [Member] | Determined by Board of Directors [Member]
Statement [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	3,600,000
Special Stock Option Plan [Member] | Determined By Chairman Member
Statement [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	100,000
KEEP Program [Member]
Statement [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	480,000
Share Based Compensation Arrangement by Share Based Payment Award Number of Shares Authorized Per Individual (in shares)	12,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	6 years
Share Based Compensation Arrangement by Share Based Payment Award Percentage of Purchased Shares Matched	50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants, Period (Year)	2 years
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent	60.00%