Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	May. 31, 2015	May. 31, 2014
Receivables, allowance	$ 2,775	$ 4,784
Intangible assets, accumulated amortization	$ 15,957	$ 12,698
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued
Common stock, par value	$ 0.30	$ 0.30
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	20,909,402	20,477,938
Treasury stock at cost, shares	546,977	0