Risk Management and Derivatives - Amounts Affecting Consolidated Statements of Income (Detail) - USD ($) $ in Millions	12 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2015
Foreign Exchange Contract | Other (income) expense, net | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (44)	$ (68)	$ 611
Embedded derivatives | Other (income) expense, net | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	(2)	(2)	(1)
Derivatives designated as cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives	94	(75)	1,480
Amount of Gain (Loss) Reclassified From Accumulated Other Comprehensive Income into Income	630	717	261
Derivatives designated as cash flow hedges | Foreign Exchange Contract | Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives	72	90	(202)
Amount of Gain (Loss) Reclassified From Accumulated Other Comprehensive Income into Income	96	(88)	(95)
Derivatives designated as cash flow hedges | Foreign Exchange Contract | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives	43	(57)	1,109
Amount of Gain (Loss) Reclassified From Accumulated Other Comprehensive Income into Income	339	586	220
Derivatives designated as cash flow hedges | Foreign Exchange Contract | Selling and administrative expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives	(4)	0	0
Amount of Gain (Loss) Reclassified From Accumulated Other Comprehensive Income into Income	0	0	0
Derivatives designated as cash flow hedges | Foreign Exchange Contract | Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives	37	(25)	497
Amount of Gain (Loss) Reclassified From Accumulated Other Comprehensive Income into Income	199	219	136
Derivatives designated as cash flow hedges | Interest rate swaps | Interest (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Other Comprehensive Income on Derivatives	(54)	(83)	76
Amount of Gain (Loss) Reclassified From Accumulated Other Comprehensive Income into Income	(4)	0	0
Derivatives designated as fair value hedges | Interest rate swaps | Interest (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ 0	$ 2	$ 5