Accumulated Other Comprehensive Income - Changes in AOCI (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance	$ 8,992	$ 11,993	$ 9,812	$ 12,407
Other comprehensive income (loss):
Other comprehensive (losses) gains before reclassifications, net of tax	254	(30)	272	(373)
Reclassifications to net income of previously deferred losses (gains), net of tax	(15)	29	29	(1)
Total other comprehensive income (loss), net of tax	239	(1)	301	(374)
Ending balance	8,729	11,758	8,729	11,758
Other comprehensive income, before reclassification, tax benefit (expense)	(3)	(8)	(4)	(24)
Reclassification from AOCI, Current Period, Tax	1	(2)	2	(3)
Foreign Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance	(301)	(169)	(173)	(191)
Other comprehensive income (loss):
Other comprehensive (losses) gains before reclassifications, net of tax	(2)	(8)	(130)	14
Reclassifications to net income of previously deferred losses (gains), net of tax	0	0	0	0
Total other comprehensive income (loss), net of tax	(2)	(8)	(130)	14
Ending balance	(303)	(177)	(303)	(177)
Other comprehensive income, before reclassification, tax benefit (expense)	0	(4)	0	(23)
Reclassification from AOCI, Current Period, Tax	0	0	0	0
Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance	210	(447)	17	(52)
Other comprehensive income (loss):
Other comprehensive (losses) gains before reclassifications, net of tax	252	(20)	394	(367)
Reclassifications to net income of previously deferred losses (gains), net of tax	(11)	28	40	(20)
Total other comprehensive income (loss), net of tax	241	8	434	(387)
Ending balance	451	(439)	451	(439)
Other comprehensive income, before reclassification, tax benefit (expense)	(3)	(4)	(4)	(1)
Reclassification from AOCI, Current Period, Tax	1	(2)	2	(3)
Net Investment Hedges
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance	115	115	115	115
Other comprehensive income (loss):
Other comprehensive (losses) gains before reclassifications, net of tax	0	0	0	0
Reclassifications to net income of previously deferred losses (gains), net of tax	0	0	0	0
Total other comprehensive income (loss), net of tax	0	0	0	0
Ending balance	115	115	115	115
Other comprehensive income, before reclassification, tax benefit (expense)	0	0	0	0
Reclassification from AOCI, Current Period, Tax	0	0	0	0
Other
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance	(54)	(85)	(51)	(85)
Other comprehensive income (loss):
Other comprehensive (losses) gains before reclassifications, net of tax	4	(2)	8	(20)
Reclassifications to net income of previously deferred losses (gains), net of tax	(4)	1	(11)	19
Total other comprehensive income (loss), net of tax	0	(1)	(3)	(1)
Ending balance	(54)	(86)	(54)	(86)
Other comprehensive income, before reclassification, tax benefit (expense)	0	0	0	0
Reclassification from AOCI, Current Period, Tax	0	0	0	0
Total
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance	(30)	(586)	(92)	(213)
Other comprehensive income (loss):
Ending balance	$ 209	$ (587)	$ 209	$ (587)