Note 9 - Commitments and Contingencies (Details) - Anticipated Payments and Insurance Proceeds of Identified Environmental Remediation Liabilities (USD $) In Thousands, unless otherwise specified	Nov. 30, 2013	Aug. 31, 2013
Anticipated Payments and Insurance Proceeds of Identified Environmental Remediation Liabilities [Abstract]
Estimated costs – current dollars	$ 4,918
Estimated costs – current dollars	2,620
Estimated costs – current dollars	1,887
Estimated costs – current dollars	865
Estimated costs – current dollars	797
Estimated costs – current dollars	12,420
Estimated costs – current dollars	23,507
Estimated insurance proceeds	0
Estimated insurance proceeds	(173)
Estimated insurance proceeds	(159)
Estimated insurance proceeds	(173)
Estimated insurance proceeds	(159)
Estimated insurance proceeds	(1,593)
Estimated insurance proceeds	(2,257)
Net anticipated costs	4,918
Net anticipated costs	2,447
Net anticipated costs	1,728
Net anticipated costs	692
Net anticipated costs	638
Net anticipated costs	10,827
Net anticipated costs	21,250
Effect of inflation	7,234
Effect of discounting	(9,054)
Balance as of November 30, 2013	$ 19,430	$ 19,680