Note 6 - Derivative Instruments - Derivatives in Cash Flow Hedging Relationships (Details) - Cash Flow Hedging [Member] - Designated as Hedging Instrument [Member] - Foreign Exchange Contract [Member] - Selling, General and Administrative Expenses [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2019	Feb. 28, 2018
Foreign currency forward contracts	$ 321	$ (1,346)	$ 2,264	$ (1,345)
Foreign currency forward contracts	$ (385)	$ 824	$ (784)	$ 1,589