SEGMENT INFORMATION Continued (Details) - USD ($) $ in Millions		12 Months Ended
		May 31, 2017	May 31, 2016	May 31, 2015
Revenues from external customers and long lived assets [Line Items]
Revenues		$ 37,728	$ 37,047	$ 38,226
Long-Lived Assets	[1]	6,728	5,428	5,119
United States [Member]
Revenues from external customers and long lived assets [Line Items]
Revenues		17,770	17,264	17,325
Long-Lived Assets	[1]	4,680	3,646	3,341
United Kingdom [Member]
Revenues from external customers and long lived assets [Line Items]
Revenues		1,999	2,349	2,388
Long-Lived Assets	[1]	402	334	309
Japan [Member]
Revenues from external customers and long lived assets [Line Items]
Revenues		1,618	1,465	1,433
Long-Lived Assets	[1]	380	375	338
Germany [Member]
Revenues from external customers and long lived assets [Line Items]
Revenues		1,417	1,438	1,466
Long-Lived Assets	[1]	116	40	33
Canada [Member]
Revenues from external customers and long lived assets [Line Items]
Revenues		1,102	1,096	1,286
Long-Lived Assets	[1]	60	44	58
Other countries [Member]
Revenues from external customers and long lived assets [Line Items]
Revenues		13,822	13,435	14,328
Long-Lived Assets	[1]	$ 1,090	$ 989	$ 1,040

[1] Long-lived assets exclude goodwill, intangible assets, equity investments and deferred taxes, which are not allocated to specific geographic locations as it is impracticable to do so.