Note 2 - Acquisitions (Details) (USD $)	0 Months Ended	3 Months Ended					3 Months Ended	0 Months Ended	3 Months Ended
	Aug. 23, 2012	Aug. 25, 2013	Aug. 26, 2012	May 26, 2013		Dec. 23, 2012	Aug. 25, 2013 GreenLine [Member] Customer Base [Member]	Apr. 23, 2012 GreenLine [Member]	Aug. 25, 2013 GreenLine [Member]
Note 2 - Acquisitions (Details) [Line Items]
Number of Processing Plants								4
Payments to Acquire Businesses, Gross	$ 62,900,000							$ 62,900,000
Business Acquisition, Escrow Deposit								4,700,000
Business Combination, Consideration Transferred	66,833,000							66,800,000
Effective Income Tax Rate Reconciliation, Percent		34.00%	37.00%						40.00%
Number of Intangible Assets Identified									2
Indefinite Lived Intangible Assets Market Value									36,000,000
Finite-lived Intangible Assets Acquired							7,500,000
Finite-Lived Intangible Asset, Useful Life							13 years
Goodwill		49,620,000		49,620,000	[1]	13,158,000			13,200,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed, Net Deferred Tax Liabilities Noncurrent									$ 1,900,000

[1] Derived from audited financial statements.