Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
May 31, 2019	May 31, 2018	May 31, 2017
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	$ 5,613	$ 4,674	$ 4,930
INVESTING ACTIVITIES
Capital expenditures	(5,490)	(5,663)	(5,116)
Business acquisitions, net of cash acquired	(66)	(179)
Proceeds from sale of business		123
Proceeds from asset dispositions and other	83	42	135
Cash used in investing activities	(5,473)	(5,677)	(4,981)
FINANCING ACTIVITIES
Principal payments on debt	(1,436)	(38)	(82)
Proceeds from debt issuances	2,463	1,480	1,190
Proceeds from stock issuances	101	327	337
Dividends paid	(683)	(535)	(426)
Purchase of treasury stock	(1,480)	(1,017)	(509)
Other, net	(4)	10	18
Cash (used in) provided by financing activities	(1,039)	227	528
Effect of exchange rate changes on cash	(47)	72	(42)
Net (decrease) increase in cash and cash equivalents	(946)	(704)	435
Cash and cash equivalents at beginning of period	3,265	3,969	3,534
Cash and cash equivalents at end of period	2,319	3,265	3,969
Consolidation Eliminations [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	(31)	32	(4)
FINANCING ACTIVITIES
Net (decrease) increase in cash and cash equivalents	(31)	32	(4)
Cash and cash equivalents at beginning of period	(15)	(47)	(43)
Cash and cash equivalents at end of period	(46)	(15)	(47)
Parent Company [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	66	(2,837)	(1,155)
INVESTING ACTIVITIES
Capital expenditures	(6)	(1)
Proceeds from asset dispositions and other	(45)	(6)	34
Cash used in investing activities	(51)	(7)	34
FINANCING ACTIVITIES
Net transfers from (to) Parent	193	1,529	421
Payment on loan between subsidiaries	51	663	41
Principal payments on debt	(1,310)
Proceeds from debt issuances	2,463	1,480	1,190
Proceeds from stock issuances	101	327	337
Dividends paid	(683)	(535)	(426)
Purchase of treasury stock	(1,480)	(1,017)	(509)
Other, net	(9)	3	(12)
Cash (used in) provided by financing activities	(674)	2,450	1,042
Effect of exchange rate changes on cash		(5)	(11)
Net (decrease) increase in cash and cash equivalents	(659)	(399)	(90)
Cash and cash equivalents at beginning of period	1,485	1,884	1,974
Cash and cash equivalents at end of period	826	1,485	1,884
Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	4,885	6,767	5,254
INVESTING ACTIVITIES
Capital expenditures	(4,920)	(5,299)	(4,694)
Business acquisitions, net of cash acquired	(9)	(44)
Proceeds from asset dispositions and other	101	33	25
Cash used in investing activities	(4,828)	(5,310)	(4,669)
FINANCING ACTIVITIES
Net transfers from (to) Parent	(259)	(1,612)	(518)
Payment on loan between subsidiaries			(15)
Intercompany dividends	106	98	1
Principal payments on debt	(117)	(22)	(55)
Other, net	127	7	(13)
Cash (used in) provided by financing activities	(143)	(1,529)	(600)
Effect of exchange rate changes on cash	(13)	4	14
Net (decrease) increase in cash and cash equivalents	(99)	(68)	(1)
Cash and cash equivalents at beginning of period	257	325	326
Cash and cash equivalents at end of period	158	257	325
Non-guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	693	712	835
INVESTING ACTIVITIES
Capital expenditures	(564)	(363)	(422)
Business acquisitions, net of cash acquired	(57)	(135)
Proceeds from sale of business		123
Proceeds from asset dispositions and other	27	15	76
Cash used in investing activities	(594)	(360)	(346)
FINANCING ACTIVITIES
Net transfers from (to) Parent	66	83	97
Payment on loan between subsidiaries	(51)	(663)	(26)
Intercompany dividends	(106)	(98)	(1)
Principal payments on debt	(9)	(16)	(27)
Other, net	(122)		43
Cash (used in) provided by financing activities	(222)	(694)	86
Effect of exchange rate changes on cash	(34)	73	(45)
Net (decrease) increase in cash and cash equivalents	(157)	(269)	530
Cash and cash equivalents at beginning of period	1,538	1,807	1,277
Cash and cash equivalents at end of period	$ 1,381	$ 1,538	$ 1,807

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

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The net cash inflow (outflow) from the proceeds and repayments made on the borrowing from one affiliate to another.

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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 financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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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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The distributions of earnings to an entity that is affiliated with the reporting entity by means of direct or indirect ownership.

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