Summary of Significant Accounting Policies - Revisions (Details) $ in Millions		3 Months Ended		6 Months Ended
	Nov. 19, 2015	Nov. 30, 2015 USD ($)	Nov. 30, 2014 USD ($)	Nov. 30, 2015 USD ($)	Nov. 30, 2014 USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock split, conversion ratio	2
Cash provided by operations:
Net income		$ 785	$ 655	$ 1,964	$ 1,617
Amortization and other				8	15
Net foreign currency adjustments				74	243
Cash provided by operations				1,036	1,547
Cash used by investing activities:
Effect of exchange rate changes on cash and equivalents				(58)	(24)
Cash used by financing activities:
Net increase (decrease) in cash and equivalents				(1)	53
Cash and equivalents, beginning of period				3,852	2,220
CASH AND EQUIVALENTS, END OF PERIOD		3,851	2,273	$ 3,851	2,273
As Reported
Cash provided by operations:
Net income					1,617
Amortization and other					(54)
Net foreign currency adjustments					0
Cash provided by operations					1,235
Cash used by investing activities:
Effect of exchange rate changes on cash and equivalents					288
Cash used by financing activities:
Net increase (decrease) in cash and equivalents					53
Cash and equivalents, beginning of period					2,220
CASH AND EQUIVALENTS, END OF PERIOD			2,273		2,273
Prior Period Revisions to Foreign Currency Adjustments
Cash used by financing activities:
Net increase (decrease) in cash and equivalents		$ 0
Prior Period Revisions to Foreign Currency Adjustments | Adjustment
Cash provided by operations:
Net income					0
Amortization and other					69
Net foreign currency adjustments					243
Cash provided by operations					312
Cash used by investing activities:
Effect of exchange rate changes on cash and equivalents					(312)
Cash used by financing activities:
Net increase (decrease) in cash and equivalents					0
Cash and equivalents, beginning of period					0
CASH AND EQUIVALENTS, END OF PERIOD			$ 0		$ 0