Note 8 - Stockholders' Equity - Cash Dividends Declared (Details) - $ / shares				3 Months Ended		6 Months Ended
	Jan. 15, 2021	Jan. 22, 2020	Oct. 22, 2019	Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2021	Feb. 29, 2020
Amount (in dollars per share)	$ 0.065	$ 0.065	$ 0.065	$ 0.065	$ 0.065	$ 0.065	$ 0.13
Record date		Feb. 05, 2020	Nov. 06, 2019
Payable date		Feb. 19, 2020	Nov. 20, 2019