Accumulated Other Comprehensive Income - Changes in AOCI (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Feb. 28, 2018	Feb. 28, 2017
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance			$ 12,407
Other comprehensive (loss) income:
Other comprehensive (losses) gains before reclassifications, net of tax	$ (120)	$ 15	(493)	$ 426
Reclassifications to net income of previously deferred losses (gains), net of tax	66	(185)	65	(515)
Total other comprehensive (loss) income, net of tax	(54)	(170)	(428)	(89)
Reclassifications to retained earnings in accordance with ASU 2018-02	17		17
Ending balance	9,782		9,782
Other comprehensive income, before reclassification, tax benefit (expense)	2	0	(22)	23
Reclassification from AOCI, Current Period, Tax	2	1	(1)	(2)
Foreign Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance	(177)	(218)	(191)	(207)
Other comprehensive (loss) income:
Other comprehensive (losses) gains before reclassifications, net of tax	51	13	65	2
Reclassifications to net income of previously deferred losses (gains), net of tax	0	(1)	0	(1)
Total other comprehensive (loss) income, net of tax	51	12	65	1
Reclassifications to retained earnings in accordance with ASU 2018-02	24		24
Ending balance	(102)	(206)	(102)	(206)
Other comprehensive income, before reclassification, tax benefit (expense)	0	0	(23)	0
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	(439)	546	(52)	463
Other comprehensive (loss) income:
Other comprehensive (losses) gains before reclassifications, net of tax	(156)	2	(523)	406
Reclassifications to net income of previously deferred losses (gains), net of tax	49	(177)	29	(498)
Total other comprehensive (loss) income, net of tax	(107)	(175)	(494)	(92)
Reclassifications to retained earnings in accordance with ASU 2018-02	(7)		(7)
Ending balance	(553)	371	(553)	371
Other comprehensive income, before reclassification, tax benefit (expense)	2	1	1	23
Reclassification from AOCI, Current Period, Tax	1	(1)	(2)	(3)
Net Investment Hedges
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance	115	115	115	115
Other comprehensive (loss) income:
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 (loss) income, net of tax	0	0	0	0
Reclassifications to retained earnings in accordance with ASU 2018-02	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	(86)	(44)	(85)	(53)
Other comprehensive (loss) income:
Other comprehensive (losses) gains before reclassifications, net of tax	(15)	0	(35)	18
Reclassifications to net income of previously deferred losses (gains), net of tax	17	(7)	36	(16)
Total other comprehensive (loss) income, net of tax	2	(7)	1	2
Reclassifications to retained earnings in accordance with ASU 2018-02	0		0
Ending balance	(84)	(51)	(84)	(51)
Other comprehensive income, before reclassification, tax benefit (expense)	0	(1)	0	0
Reclassification from AOCI, Current Period, Tax	1	2	1	1
Total
AOCI Including Portion Attributable to Noncontrolling, Net of Tax [Roll Forward]
Beginning balance	(587)	399	(213)	318
Other comprehensive (loss) income:
Ending balance	$ (624)	$ 229	$ (624)	$ 229