9. Cancellation of Capital Stock (Details) - USD ($)	3 Months Ended
	Aug. 31, 2016	May 31, 2016	Aug. 31, 2015	May 31, 2015	Nov. 30, 2014
Details
Stock Repurchased and Retired During Period, Shares	112,152	63,386	4,778	89,051	118,969
Payments for Repurchase of Common Stock	$ 1,378,701	$ 745,878	$ 54,491	$ 1,101,574	$ 1,292,477
Average price per share repurchased and cancelled	$ 12.29	$ 11.77	$ 11.41	$ 12.37	$ 10.86
Cumulative Effect on Retained Earnings, before Tax	$ 1,325,994		$ 52,236	$ 1,059,554	$ 1,236,340
Shares returned to treasury for cancellation	15,000		15,000
Shares returned to treasury for cancellation, value	$ 7,124		$ 7,077
Shares returned to treasury for cancellation, value, effect on retained earnings	$ 7,124	$ 715,756