Consolidated Statements of Stockholders' Equity - USD ($)	Common Stock	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Beginning balance, shares at May. 31, 2019	4,032,878
Beginning balance at May. 31, 2019	$ 13,245,439	$ (527,827)	$ (4,244,679)	$ 8,472,933
Share repurchases, shares	(412,422)
Share repurchases, amount	$ (1,333,399)			(1,333,399)
Shares issued to directors and officers upon vesting of RSUs, amount	$ 326,724			326,724
Exercise of stock options, shares	33,166
Exercise of stock options, amount	$ 8,500			8,500
Restricted stock units exercised, shares	129,863
Restricted stock units exercised, amount	$ 0			0
Other comprehensive income		527,827		527,827
Net income			4,556,656	4,556,656
Ending balance, shares at Feb. 29, 2020	3,783,485
Ending balance at Feb. 29, 2020	$ 12,247,264	0	311,977	12,559,241
Beginning balance, shares at May. 31, 2020	3,784,554
Beginning balance at May. 31, 2020	$ 12,257,306	0	(364,104)	11,893,202
Share repurchases, shares	(72,101)
Share repurchases, amount	$ (234,517)			(234,517)
Shares issued to directors and officers upon vesting of RSUs, shares	77,281
Shares issued to directors and officers upon vesting of RSUs, amount				0
Stock-based compensation	$ 163,493			163,493
Repurchase of restricted stock units, shares	(14,400)
Repurchase of restricted stock units, amount	$ (65,975)			(65,975)
Net income			(4,635,607)	(4,635,607)
Ending balance, shares at Feb. 28, 2021	3,775,334
Ending balance at Feb. 28, 2021	$ 12,120,307	$ 0	$ (4,999,711)	$ 7,120,596