Accumulated Other Comprehensive Income - Reclassification out of AOCI (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	$ (3,605)	$ (3,425)	$ (7,444)	$ (7,071)
Selling and administrative expense	(2,088)	(1,836)	(4,144)	(3,895)
Other expense (income), net	(13)	17	(41)	45
Total before tax	717	712	1,757	1,512
Tax (expense) benefit	(180)	(191)	(440)	(406)
NET INCOME FROM CONTINUING OPERATIONS	537	521	1,317	1,106
November 30, 2013
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
NET INCOME FROM CONTINUING OPERATIONS	14		43
Gain (losses) on cash flow hedges | November 30, 2013
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	20		55
Tax (expense) benefit	(5)		(10)
NET INCOME FROM CONTINUING OPERATIONS	15		45
Gain (losses) on cash flow hedges | Foreign exchange forwards and options | November 30, 2013
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Revenue	7		21
Cost of sales	7		23
Selling and administrative expense	0		0
Other expense (income), net	6		11
Other | November 30, 2013
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other expense (income), net	(1)		(2)
Total before tax	(1)		(2)
Tax (expense) benefit	0		0
NET INCOME FROM CONTINUING OPERATIONS	$ (1)		$ (2)