Capital Stock and Stock-Based Awards (Details) - Schedule of stock option activity for the Class A Stock and Common Stock plans (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	May 31, 2013
Schedule of stock option activity for the Class A Stock and Common Stock plans [Abstract]
Outstanding at May 31, 2012	4,948,075
Outstanding at May 31, 2012 (in Dollars per share)	$ 29.69
Granted	86,614
Granted (in Dollars per share)	$ 31.96
Exercised	(475,432)
Exercised (in Dollars per share)	$ 27.29
Expired	(348,840)
Expired (in Dollars per share)	$ 35.89
Cancellations and forfeitures	(24,937)
Cancellations and forfeitures (in Dollars per share)	$ 32.72
Outstanding at May 31, 2013	4,185,480
Outstanding at May 31, 2013 (in Dollars per share)	$ 29.49
Outstanding at May 31, 2013	4 years 292 days
Outstanding at May 31, 2013 (in Dollars)	$ 9.7
Exercisable at May 31, 2013	3,370,439
Exercisable at May 31, 2013 (in Dollars per share)	$ 30.25
Exercisable at May 31, 2013	4 years
Exercisable at May 31, 2013 (in Dollars)	$ 6.5