Note 11 - Commitments and Contingencies (Details) - Anticipated Payments and Insurance Proceeds of Identified Environmental Remediation Liabilities - USD ($) $ in Thousands	Aug. 29, 2015	Aug. 30, 2014	Aug. 31, 2013
Anticipated Payments and Insurance Proceeds of Identified Environmental Remediation Liabilities [Abstract]
Estimated costs – current dollars	$ 7,413
Estimated costs – current dollars	1,829
Estimated costs – current dollars	1,476
Estimated costs – current dollars	1,309
Estimated costs – current dollars	1,361
Estimated costs – current dollars	12,493
Estimated costs – current dollars	25,881
Estimated insurance proceeds	(159)
Estimated insurance proceeds	(173)
Estimated insurance proceeds	(159)
Estimated insurance proceeds	(173)
Estimated insurance proceeds	(159)
Estimated insurance proceeds	(1,293)
Estimated insurance proceeds	(2,116)
Net anticipated costs	7,254
Net anticipated costs	1,656
Net anticipated costs	1,317
Net anticipated costs	1,136
Net anticipated costs	1,202
Net anticipated costs	11,200
Net anticipated costs	23,765
Effect of inflation	7,255
Effect of discounting	(7,713)
Balance as of August 29, 2015	$ 23,307	$ 19,846	$ 19,680