Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Nov. 30, 2011	May 31, 2011
Consolidated Balance Sheets [Abstract]
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	100,000	100,000
Common stock, shares issued	27,894	27,887
Common stock, shares outstanding	27,894	27,887