Note 5 - Derivative Instruments - Fair Value Amounts of Derivative Instruments and Gains (Details) - Foreign Exchange Contract [Member] - Cash Flow Hedging [Member] - Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	May 31, 2017	Aug. 31, 2016
Prepaid Expenses and Other Current Assets [Member]
Derivative assets	$ 2,738	$ 163
Other Assets [Member]
Derivative assets	2,730	706
Accounts Payable and Accrued Liabilities [Member]
Derivative liabilities	$ 596	$ 2,791