Weighted-Average Shares and Reconciliation - Schedule of Weighted-Average Number of Shares (Details) - shares	3 Months Ended		9 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Net income (loss) per common share
Weighted-average shares (basic)	3,788,315	3,764,536	3,790,022	3,759,369
Effect of dilutive stock options			23,653
Weighted-average shares (diluted)	3,788,315	3,764,536	3,813,675	3,759,369