XML 49 R37.htm IDEA: XBRL DOCUMENT v3.7.0.1
Other Assets - Additional Information (Detail) - USD ($)
May 31, 2017
May 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]    
Cash surrender value of life insurance $ 7,093,000 $ 6,885,000