Risk Management and Derivatives - FV of Derivative Instruments Included within Consolidated Balance Sheet (Detail) - USD ($) $ in Millions	Aug. 31, 2015	May. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 1,154	$ 1,639
Derivative Liabilities	147	175
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	1,036	1,423
Derivative Liabilities	100	144
Designated as Hedging Instrument | Foreign exchange forwards and options | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	662	825
Designated as Hedging Instrument | Foreign exchange forwards and options | Deferred income taxes and other long-term assets
Derivatives, Fair Value [Line Items]
Derivative Assets	298	520
Designated as Hedging Instrument | Foreign exchange forwards and options | Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	90	140
Designated as Hedging Instrument | Foreign exchange forwards and options | Deferred income taxes and other long-term liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	10	4
Designated as Hedging Instrument | Interest rate swap | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	76	78
Designated as Hedging Instrument | Interest rate swap | Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	0	0
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	118	216
Derivative Liabilities	47	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	109	209
Derivatives not designated as hedging instruments | Foreign exchange forwards and options | Deferred income taxes and other long-term assets
Derivatives, Fair Value [Line Items]
Derivative Assets	1	0
Derivative Liabilities	9	0
Derivatives not designated as hedging instruments | Foreign exchange forwards and options | Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	26	20
Derivatives not designated as hedging instruments | Embedded derivatives | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	4	2
Derivatives not designated as hedging instruments | Embedded derivatives | Deferred income taxes and other long-term assets
Derivatives, Fair Value [Line Items]
Derivative Assets	4	5
Derivative Liabilities	10	9
Derivatives not designated as hedging instruments | Embedded derivatives | Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 2	$ 2