Risk Management and Derivatives - FV of Derivative Instruments Included within Consolidated Balance Sheet (Detail) - USD ($) $ in Millions	Aug. 31, 2018	May 31, 2018
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 485	$ 400
Derivative Liabilities	111	190
Derivatives formally designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	335	270
Derivative Liabilities	72	156
Derivatives formally designated as hedging instruments | Foreign exchange forwards and options | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	207	118
Derivatives formally designated as hedging instruments | Foreign exchange forwards and options | Deferred income taxes and other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	128	152
Derivatives formally designated as hedging instruments | Foreign exchange forwards and options | Accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	72	156
Derivatives formally designated as hedging instruments | Foreign exchange forwards and options | Deferred income taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	0	0
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	150	130
Derivative Liabilities	39	34
Derivatives not designated as hedging instruments | Foreign exchange forwards and options | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	140	119
Derivatives not designated as hedging instruments | Foreign exchange forwards and options | Deferred income taxes and other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	1	0
Derivatives not designated as hedging instruments | Foreign exchange forwards and options | Accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	27	26
Derivatives not designated as hedging instruments | Foreign exchange forwards and options | Deferred income taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	0	0
Derivatives not designated as hedging instruments | Embedded derivatives | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	3	3
Derivatives not designated as hedging instruments | Embedded derivatives | Deferred income taxes and other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	6	8
Derivatives not designated as hedging instruments | Embedded derivatives | Accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	3	2
Derivatives not designated as hedging instruments | Embedded derivatives | Deferred income taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 9	$ 6