2. SUMMARY - Earnings per share (Details) - USD ($)	3 Months Ended							9 Months Ended
	May 31, 2020	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	May 31, 2020	May 31, 2019
Numerator
Net income attributable to common shareholders	$ 2,935,569	$ 2,150,080	$ 2,058,277	$ 2,059,227	$ 2,888,706	$ 2,099,449	$ 1,535,947	$ 7,143,925	$ 6,524,102
Denominator
Weighted-average number of common shares outstanding during the period	17,735,354				17,519,849			17,661,189	17,472,922
Dilutive effect of stock options	691,518				576,346			672,407	535,414
Common stock and common stock equivalents used for diluted earnings per share	18,426,872				18,096,195			18,333,596	18,008,336