Accumulated Other Comprehensive Income - Changes in AOCI (Detail) - USD ($) $ in Millions	12 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 12,258	$ 12,707	$ 10,824
Other comprehensive gains (losses) before reclassifications, net of tax	119	(219)
Reclassifications to net income of previously deferred (gains) losses, net of tax	(650)	(709)
Total other comprehensive income (loss), net of tax	(531)	(928)	1,161
Ending balance	12,407	12,258	12,707
Other comprehensive income, before reclassification, tax benefit (expense)	27	26
Reclassification from AOCI, current period, tax expense (benefit)	(6)	9
Foreign Currency Translation Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(207)	(31)
Other comprehensive gains (losses) before reclassifications, net of tax	15	(178)
Reclassifications to net income of previously deferred (gains) losses, net of tax	1	2
Total other comprehensive income (loss), net of tax	16	(176)
Ending balance	(191)	(207)	(31)
Other comprehensive income, before reclassification, tax benefit (expense)	0	0
Reclassification from AOCI, current period, tax expense (benefit)	0	0
Cash Flow Hedges
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	463	1,220
Other comprehensive gains (losses) before reclassifications, net of tax	118	(47)
Reclassifications to net income of previously deferred (gains) losses, net of tax	(633)	(710)
Total other comprehensive income (loss), net of tax	(515)	(757)
Ending balance	(52)	463	1,220
Other comprehensive income, before reclassification, tax benefit (expense)	24	28
Reclassification from AOCI, current period, tax expense (benefit)	(3)	7
Net Investment Hedges
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	115	115
Other comprehensive gains (losses) before reclassifications, net of tax	0	0
Reclassifications to net income of previously deferred (gains) losses, net of tax	0	0
Total other comprehensive income (loss), net of tax	0	0
Ending balance	115	115	115
Other comprehensive income, before reclassification, tax benefit (expense)	0	0
Reclassification from AOCI, current period, tax expense (benefit)	0	0
Other
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(53)	(58)
Other comprehensive gains (losses) before reclassifications, net of tax	(14)	6
Reclassifications to net income of previously deferred (gains) losses, net of tax	(18)	(1)
Total other comprehensive income (loss), net of tax	(32)	5
Ending balance	(85)	(53)	(58)
Other comprehensive income, before reclassification, tax benefit (expense)	3	(2)
Reclassification from AOCI, current period, tax expense (benefit)	(3)	2
Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	318	1,246
Ending balance	$ (213)	$ 318	$ 1,246