Note 9 - Stock-Based Compensation (Details) (USD $)	12 Months Ended							12 Months Ended
	Apr. 27, 2013	Apr. 28, 2012	Apr. 30, 2011	Apr. 27, 2013 Stock Options or Stock Awards [Member] Omnibus Plan [Member]	Apr. 27, 2013 SARS, Dividend Equivalents and Other Awards [Member] Omnibus Plan [Member]	Apr. 27, 2013 Determined by Board of Directors [Member] Special Stock Option Plan [Member]	Apr. 27, 2013 Determined by Chairman [Member] Other Plan [Member]	Apr. 27, 2013 Omnibus Plan [Member]	Apr. 27, 2013 KEEP Program [Member]	Apr. 28, 2012 KEEP Program [Member]
Note 9 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)				4,800,000	4,800,000	1,800,000	50,000		240,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Per Individual (in Shares)								1,680,000	6,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period								5 years	6 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period								10 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, Purchase Price of Common Stock, Percent									60.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in Shares)	2,000		301,500						2,000	3,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	8 years	8 years	7 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	38.10%	42.90%	48.60%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	1.60%	2.50%	2.80%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	5.00%	5.30%	4.30%
Share-based Compensation	$ 230,000	$ 290,000	$ 446,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	453,000	513,000	135,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	406,000	758,000	799,000
Proceeds from Stock Options Exercised	239,000	115,000	209,000
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options	92,000	295,000	921,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in Dollars per share)	$ 8.76	$ 8.16	$ 6.35
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	375,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 328 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	4 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	3,400,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	3 years 219 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value	$ 2,400,000
Employee Stock Ownership Plan (ESOP), Shares in ESOP (in Shares)	1,536,000