Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017	May 31, 2019	May 31, 2018
EPS:
Net income	$ 2,944	$ 1,961	$ 1,925	$ 2,253	$ 1,319	$ 1,195	$ 6,830	$ 4,767
Less: accrued preferred stock dividends	(19)			(19)			(57)	(57)
Net income attributable to common shareholders	$ 2,925			$ 2,234			$ 6,773	$ 4,710
Earnings per common share - basic and diluted	$ 0.60			$ 0.46			$ 1.39	$ 0.97