Consolidated Statements Of Equity (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	May 31, 2012	May 31, 2011	May 31, 2010
Pension liability adjustment, tax	$ 4,975	$ (760)	$ 1,163
Cash flow hedges, tax	$ 318	$ 563	$ 854
Cash dividend declared, per share	$ 0.48	$ 0.40	$ 0.40