Geographic Information (Detail) - Financial information about foreign and domestic operations and export sales (USD $)	3 Months Ended
	Aug. 31, 2012	Aug. 31, 2011
Revenues from sales to unaffiliated customers	$ 1,701,949	$ 1,407,665
United States
Revenues from sales to unaffiliated customers	279,509	186,449
Asia
Revenues from sales to unaffiliated customers	901,666	631,752
Europe
Revenues from sales to unaffiliated customers	508,167	580,918
South America
Revenues from sales to unaffiliated customers	236	1,357
Middle East
Revenues from sales to unaffiliated customers	11,385	4,170
Other
Revenues from sales to unaffiliated customers	$ 986	$ 3,019