Note 9 - Accrued Liabilities (Details) - Summary of current and long term accrued liabilities (USD $) In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 25, 2012
Summary of current and long term accrued liabilities [Abstract]
Payroll and benefit related	$ 39,119	$ 31,825
Insurance related	36,095	35,374
Environmental related	5,158	5,100
Other	6,622	5,875
	86,994	78,174
Benefit related	19,719	18,380
Environmental related	14,522	14,920
Asset retirement obligations	10,796	10,120
	45,037	43,420
Total accrued liabilities	$ 132,031	$ 121,594