Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Feb. 28, 2019	Feb. 28, 2019	Feb. 28, 2018
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES		$ 3,323	$ 1,162
INVESTING ACTIVITIES
Capital expenditures		(3,757)	(3,994)
Business acquisitions, net of cash acquired			(44)
Proceeds from asset dispositions and other		62	21
Cash used in investing activities		(3,695)	(4,017)
FINANCING ACTIVITIES
Proceeds from short-term borrowings, net		220	797
Proceeds from debt issuances		2,463	1,481
Principal payments on debt		(874)	(31)
Proceeds from stock issuances		58	284
Dividends paid		(514)	(402)
Purchase of treasury stock	$ (93)	(1,365)	(558)
Other, net		5	6
Cash (used in) provided by financing activities		(7)	1,577
Effect of exchange rate changes on cash		(14)	98
Net (decrease) increase in cash and cash equivalents		(393)	(1,180)
Cash and cash equivalents at beginning of period		3,265	3,969
Cash and cash equivalents at end of period	2,872	2,872	2,789
Consolidation Eliminations [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES		(26)	10
FINANCING ACTIVITIES
Net (decrease) increase in cash and cash equivalents		(26)	10
Cash and cash equivalents at beginning of period		(15)	(47)
Cash and cash equivalents at end of period	(41)	(41)	(37)
Parent Company [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES		(109)	(3,537)
INVESTING ACTIVITIES
Capital expenditures		(3)
Proceeds from asset dispositions and other		(45)	(5)
Cash used in investing activities		(48)	(5)
FINANCING ACTIVITIES
Proceeds from short-term borrowings, net		220	797
Net transfers from (to) Parent		2	807
Payment on loan between subsidiaries		(29)	210
Proceeds from debt issuances		2,463	1,481
Principal payments on debt		(750)
Proceeds from stock issuances		58	284
Dividends paid		(514)	(402)
Purchase of treasury stock		(1,365)	(558)
Other, net			2
Cash (used in) provided by financing activities		85	2,621
Effect of exchange rate changes on cash			(6)
Net (decrease) increase in cash and cash equivalents		(72)	(927)
Cash and cash equivalents at beginning of period		1,485	1,884
Cash and cash equivalents at end of period	1,413	1,413	957
Guarantor Subsidiaries [Member[ \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES		3,136	4,664
INVESTING ACTIVITIES
Capital expenditures		(3,359)	(3,746)
Business acquisitions, net of cash acquired			(44)
Proceeds from asset dispositions and other		86	23
Cash used in investing activities		(3,273)	(3,767)
FINANCING ACTIVITIES
Net transfers from (to) Parent		(31)	(895)
Intercompany dividends		114
Principal payments on debt		(117)	(17)
Other, net		127	4
Cash (used in) provided by financing activities		93	(908)
Effect of exchange rate changes on cash		(9)	61
Net (decrease) increase in cash and cash equivalents		(53)	50
Cash and cash equivalents at beginning of period		257	325
Cash and cash equivalents at end of period	204	204	375
Non Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES		322	25
INVESTING ACTIVITIES
Capital expenditures		(395)	(248)
Proceeds from asset dispositions and other		21	3
Cash used in investing activities		(374)	(245)
FINANCING ACTIVITIES
Net transfers from (to) Parent		29	88
Payment on loan between subsidiaries		29	(210)
Intercompany dividends		(114)
Principal payments on debt		(7)	(14)
Other, net		(122)
Cash (used in) provided by financing activities		(185)	(136)
Effect of exchange rate changes on cash		(5)	43
Net (decrease) increase in cash and cash equivalents		(242)	(313)
Cash and cash equivalents at beginning of period		1,538	1,807
Cash and cash equivalents at end of period	$ 1,296	$ 1,296	$ 1,494

The net cash inflow (outflow) from parent as a source of financing.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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