Note 6 - Capital Stock and Transactions With Related Parties (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended			96 Months Ended
	Jan. 29, 2019	Aug. 04, 2017	May 02, 2020	Apr. 27, 2019	Apr. 28, 2018	May 02, 2020	Apr. 30, 2012
Stock Repurchase Program, Number of Shares Authorized to be Repurchased (in shares)							1,600,000
Treasury Stock, Shares, Acquired (in shares)			154,512			656,572
Treasury Stock, Value, Acquired, Cost Method			$ 6,200
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased (in shares)			943,428			943,428
Payments of Ordinary Dividends, Common Stock	$ 135,200	$ 69,900	$ (0)	$ 135,247	$ 69,878
Common Stock, Dividends, Per Share, Cash Paid (in dollars per share)	$ 2.90	$ 1.50
Treasury Stock, Shares, Acquired			0
CMA [Member]
Averaged Operating Costs			8,000	8,000	8,000
Averaged Lease Buy-down Payments and Financing Costs			8,000	8,000	8,000
Related Party Transaction, Amounts of Transaction			10,000	10,200	$ 9,800
Accounts Payable, Total			$ 2,600	$ 2,400		$ 2,600