Consolidated Balance Sheets (Parentheticals) (USD $) In Thousands, except Share data	May 31, 2011	May 31, 2010
Allowance for doubtful accounts (in Dollars)	$ 2,157	$ 2,122
Common stock, par value (in Dollars per share)	$ 0.10	$ 0.10
Common stock, authorized shares	120,000,000	120,000,000
Common stock, issued	70,367,219	69,912,449
Common stock, outstanding	70,367,219	69,912,449