Short-Term Debt and Credit Arrangements (Details Textual) (USD $)	Feb. 28, 2014	May 31, 2013	Oct. 28, 2013 Three-year agreement maturing on October 28, 2016	Oct. 28, 2013 Four-year agreement maturing on October 28, 2017	Oct. 28, 2013 Five-year agreement maturing on October 28, 2018	Feb. 28, 2014 Revolving credit agreements	May 31, 2013 Revolving credit agreements
Maximum borrowing capacity lines of credit			$ 1,006,000,000	$ 1,088,000,000	$ 1,033,000,000	$ 3,445,000,000	$ 3,100,000,000
Maximum borrowing capacity letters of credit						100,000,000
Line of Credit Facility, Amount Outstanding	$ 0	$ 0