Risk Management and Derivatives - FV of Derivative Instruments Included within Consolidated Balance Sheet (Detail) - USD ($) $ in Millions	Feb. 29, 2016	May. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 968	$ 1,639
Derivative Liabilities	182	175
Derivatives formally designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	884	1,423
Derivative Liabilities	94	144
Derivatives formally designated as hedging instruments | Foreign exchange forwards and options | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	657	825
Derivatives formally designated as hedging instruments | Foreign exchange forwards and options | Deferred income taxes and other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	227	520
Derivatives formally designated as hedging instruments | Foreign exchange forwards and options | Accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	26	140
Derivatives formally designated as hedging instruments | Foreign exchange forwards and options | Deferred income taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	14	4
Derivatives formally designated as hedging instruments | Interest rate swaps | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	0	78
Derivatives formally designated as hedging instruments | Interest rate swaps | Accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	54	0
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	84	216
Derivative Liabilities	88	31
Derivatives not designated as hedging instruments | Foreign exchange forwards and options | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	63	209
Derivatives not designated as hedging instruments | Foreign exchange forwards and options | Deferred income taxes and other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	16	0
Derivatives not designated as hedging instruments | Foreign exchange forwards and options | Accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	77	20
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	1	2
Derivatives not designated as hedging instruments | Embedded derivatives | Deferred income taxes and other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	4	5
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	$ 8	$ 9