Other Property (Detail) - USD ($) $ in Thousands	May. 31, 2015	May. 31, 2014
Property, Plant and Equipment [Abstract]
Land	$ 6,985	$ 6,985
Buildings	15,895	15,784
Furniture and other equipment	6,733	9,118
Leasehold improvements	256	218
Property, Plant and Equipment, Gross, Total	29,869	32,105
Less-accumulated depreciation and amortization	(16,749)	(18,983)
Total	$ 13,120	$ 13,122