Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
May 31, 2018	May 31, 2017	May 31, 2016
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	$ 4,674	$ 4,930	$ 5,708
INVESTING ACTIVITIES
Capital expenditures	(5,663)	(5,116)	(4,818)
Business acquisitions, net of cash acquired	(179)		(4,618)
Proceeds from sale of business	123
Proceeds from asset dispositions and other	42	135	(10)
Cash used in investing activities	(5,677)	(4,981)	(9,446)
FINANCING ACTIVITIES
Principal payments on debt	(38)	(82)	(41)
Proceeds from debt issuances	1,480	1,190	6,519
Proceeds from stock issuances	327	337	183
Dividends paid	(535)	(426)	(277)
Purchase of treasury stock	(1,017)	(509)	(2,722)
Other, net	10	18	(51)
Cash provided by financing activities	227	528	3,611
Effect of exchange rate changes on cash	72	(42)	(102)
Net (decrease) increase in cash and cash equivalents	(704)	435	(229)
Cash and cash equivalents at beginning of period	3,969	3,534	3,763
Cash and cash equivalents at end of period	3,265	3,969	3,534
Consolidation Eliminations [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	32	(4)	35
FINANCING ACTIVITIES
Net (decrease) increase in cash and cash equivalents	32	(4)	35
Cash and cash equivalents at beginning of period	(47)	(43)	(78)
Cash and cash equivalents at end of period	(15)	(47)	(43)
Parent Company [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	(2,837)	(1,155)	(831)
INVESTING ACTIVITIES
Capital expenditures	(1)
Proceeds from asset dispositions and other	(6)	34	(55)
Cash used in investing activities	(7)	34	(55)
FINANCING ACTIVITIES
Net transfers from (to) Parent	1,529	421	1,629
Payment on loan between subsidiaries	663	41	(4,805)
Proceeds from debt issuances	1,480	1,190	6,519
Proceeds from stock issuances	327	337	183
Dividends paid	(535)	(426)	(277)
Purchase of treasury stock	(1,017)	(509)	(2,722)
Other, net	3	(12)	(51)
Cash provided by financing activities	2,450	1,042	476
Effect of exchange rate changes on cash	(5)	(11)	1
Net (decrease) increase in cash and cash equivalents	(399)	(90)	(409)
Cash and cash equivalents at beginning of period	1,884	1,974	2,383
Cash and cash equivalents at end of period	1,485	1,884	1,974
Guarantor Subsidiaries [Member[ \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	6,767	5,254	5,932
INVESTING ACTIVITIES
Capital expenditures	(5,299)	(4,694)	(4,617)
Business acquisitions, net of cash acquired	(44)
Proceeds from asset dispositions and other	33	25	33
Cash used in investing activities	(5,310)	(4,669)	(4,584)
FINANCING ACTIVITIES
Net transfers from (to) Parent	(1,612)	(518)	(1,549)
Payment on loan between subsidiaries		(15)	109
Intercompany dividends	98	1	20
Principal payments on debt	(22)	(55)	(19)
Other, net	7	(13)	(48)
Cash provided by financing activities	(1,529)	(600)	(1,487)
Effect of exchange rate changes on cash	4	14	(22)
Net (decrease) increase in cash and cash equivalents	(68)	(1)	(161)
Cash and cash equivalents at beginning of period	325	326	487
Cash and cash equivalents at end of period	257	325	326
Non Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	712	835	572
INVESTING ACTIVITIES
Capital expenditures	(363)	(422)	(201)
Business acquisitions, net of cash acquired	(135)		(4,618)
Proceeds from sale of business	123
Proceeds from asset dispositions and other	15	76	12
Cash used in investing activities	(360)	(346)	(4,807)
FINANCING ACTIVITIES
Net transfers from (to) Parent	83	97	(80)
Payment on loan between subsidiaries	(663)	(26)	4,696
Intercompany dividends	(98)	(1)	(20)
Principal payments on debt	(16)	(27)	(22)
Other, net		43	48
Cash provided by financing activities	(694)	86	4,622
Effect of exchange rate changes on cash	73	(45)	(81)
Net (decrease) increase in cash and cash equivalents	(269)	530	306
Cash and cash equivalents at beginning of period	1,807	1,277	971
Cash and cash equivalents at end of period	$ 1,538	$ 1,807	$ 1,277

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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Payments for proceeds from asset dispositions and other.

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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 increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the 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. Includes effect from exchange rate changes.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of increase (decrease) from the effect of exchange rate changes on cash and cash equivalent balances held in foreign currencies.

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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 cash outflow to reacquire common stock during the period.

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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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Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

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The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

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The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity.

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The cash outflow associated with security instruments that either represent a creditor or an ownership relationship with the holder of the investment security with a maturity of beyond one year or normal operating cycle, if longer. Includes repayments of (a) debt, (b) capital lease obligations, (c) mandatory redeemable capital securities, and (d) any combination of (a), (b), or (c).

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