Note 18 - Subsequent Events (Details Textual) - $ / shares										12 Months Ended
	Oct. 22, 2019	Jul. 24, 2019	Apr. 25, 2019	Jan. 23, 2019	Oct. 24, 2018	Jul. 25, 2018	Apr. 25, 2018	Jan. 24, 2018	Nov. 20, 2017	Aug. 31, 2019	Aug. 31, 2018
Common Stock, Dividends, Per Share, Declared		$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.24	$ 0.20
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared	$ 0.065