Fair Value Measurements - Derivative Assets and Liabilities at Fair Value (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Feb. 28, 2015		Feb. 28, 2014	Feb. 28, 2015		Feb. 28, 2014	May 31, 2014
Derivatives, Fair Value [Line Items]
Accrued Liabilities	$ 167			$ 167			$ 85
Collateral received from counterparties to hedging instruments	769			769			0
Investment Income, Interest	1		2	4		4
Fair Value, Measurements, Recurring
Derivatives, Fair Value [Line Items]
Reduction in derivative assets if netted	193			193			63
Reduction in derivative liabilities if netted	193			193			63
Fair Value Measurements Using Level 2 | Fair Value, Measurements, Recurring
Derivatives, Fair Value [Line Items]
Assets at Fair Value	1,507			1,507			133	[1]
Other Current Assets	1,053			1,053			101	[1]
Other Long-term Assets	454			454			32	[1]
Liabilities at Fair Value	195			195			85
Accrued Liabilities	167			167			84	[1]
Other Long-term Liabilities	28			28			1	[1]
Fair Value Measurements Using Level 2 | Fair Value, Measurements, Recurring | Foreign exchange forwards and options
Derivatives, Fair Value [Line Items]
Assets at Fair Value	1,459	[2]		1,459	[2]		127	[1]
Other Current Assets	1,005	[2]		1,005	[2]		101	[1]
Other Long-term Assets	454	[2]		454	[2]		26	[1]
Liabilities at Fair Value	195	[2]		195	[2]		85	[1]
Accrued Liabilities	167	[2]		167	[2]		84	[1]
Other Long-term Liabilities	28	[2]		28	[2]		1	[1]
Fair Value Measurements Using Level 2 | Fair Value, Measurements, Recurring | Embedded derivatives
Derivatives, Fair Value [Line Items]
Assets at Fair Value	1			1
Other Current Assets	1			1
Other Long-term Assets	0			0
Liabilities at Fair Value	0			0
Accrued Liabilities	0			0
Other Long-term Liabilities	0			0
Fair Value Measurements Using Level 2 | Fair Value, Measurements, Recurring | Interest rate swap
Derivatives, Fair Value [Line Items]
Assets at Fair Value	47	[3]		47	[3]		6	[1]
Other Current Assets	47	[3]		47	[3]		0	[1]
Other Long-term Assets	0	[3]		0	[3]		6	[1]
Liabilities at Fair Value	0	[3]		0	[3]		0	[1]
Accrued Liabilities	0	[3]		0	[3]		0	[1]
Other Long-term Liabilities	0	[3]		0	[3]		0	[1]
Accrued Liabilities
Derivatives, Fair Value [Line Items]
Collateral received from counterparties to hedging instruments	769			769
Accrued Liabilities | Foreign exchange forwards and options
Derivatives, Fair Value [Line Items]
Collateral received from counterparties to hedging instruments	736			736
Accrued Liabilities | Interest rate swap
Derivatives, Fair Value [Line Items]
Collateral received from counterparties to hedging instruments	33			33
Securities Pledged as Collateral
Derivatives, Fair Value [Line Items]
Collateral received from counterparties to hedging instruments	$ 77			$ 77

[1] If the foreign exchange derivative instruments had been netted on the Consolidated Balance Sheets, the asset and liability positions each would have been reduced by $63 million as of May 31, 2014. No amounts of collateral were received or posted on the Company’s derivative assets and liabilities as of May 31, 2014.

[2] If the foreign exchange derivative instruments had been netted on the Unaudited Condensed Consolidated Balance Sheets, the asset and liability positions each would have been reduced by $193 million as of February 28, 2015. As of that date, the Company had received $736 million of cash collateral and $77 million of securities from various counterparties related to these foreign exchange derivative instruments. No amount of collateral was posted on the Company’s derivative liability balance as of February 28, 2015.

[3] As of February 28, 2015, the Company had received $33 million of cash collateral related to its interest rate swaps.