Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended
Aug. 31, 2019	Aug. 31, 2018
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	$ 565	$ 701
INVESTING ACTIVITIES
Capital expenditures	(1,418)	(1,179)
Proceeds from asset dispositions and other	(1)	78
Cash used in investing activities	(1,419)	(1,101)
FINANCING ACTIVITIES
Proceeds from short-term borrowings, net		299
Proceeds from debt issuances	2,093
Principal payments on debt	(985)	(2)
Proceeds from stock issuances	12	25
Dividends paid	(170)	(173)
Purchase of treasury stock	(3)	(625)
Other, net	(5)	4
Cash provided by (used in) financing activities	942	(472)
Effect of exchange rate changes on cash	(18)	(24)
Net increase (decrease) in cash and cash equivalents	70	(896)
Cash and cash equivalents at beginning of period	2,319	3,265
Cash and cash equivalents at end of period	2,389	2,369
Consolidation Eliminations [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	(23)	(27)
FINANCING ACTIVITIES
Net increase (decrease) in cash and cash equivalents	(23)	(27)
Cash and cash equivalents at beginning of period	(46)	(15)
Cash and cash equivalents at end of period	(69)	(42)
Parent Company [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	(1,671)	785
INVESTING ACTIVITIES
Capital expenditures	(2)
Proceeds from asset dispositions and other	(10)	(5)
Cash used in investing activities	(12)	(5)
FINANCING ACTIVITIES
Proceeds from short-term borrowings, net		299
Net transfers from (to) Parent	1,002	(853)
Payment on loan between subsidiaries	(434)
Proceeds from debt issuances	2,093
Principal payments on debt	(956)
Proceeds from stock issuances	12	25
Dividends paid	(170)	(173)
Purchase of treasury stock	(3)	(625)
Other, net	(3)
Cash provided by (used in) financing activities	1,541	(1,327)
Net increase (decrease) in cash and cash equivalents	(142)	(547)
Cash and cash equivalents at beginning of period	826	1,485
Cash and cash equivalents at end of period	684	938
Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	2,111	(159)
INVESTING ACTIVITIES
Capital expenditures	(1,317)	(983)
Proceeds from asset dispositions and other	5	78
Cash used in investing activities	(1,312)	(905)
FINANCING ACTIVITIES
Net transfers from (to) Parent	(1,059)	763
Intercompany dividends	304	81
Principal payments on debt	(27)
Other, net		148
Cash provided by (used in) financing activities	(782)	992
Effect of exchange rate changes on cash	1	(5)
Net increase (decrease) in cash and cash equivalents	18	(77)
Cash and cash equivalents at beginning of period	158	257
Cash and cash equivalents at end of period	176	180
Non-guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Condensed Cash Flow Statements Captions [Line Items]
CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	148	102
INVESTING ACTIVITIES
Capital expenditures	(99)	(196)
Proceeds from asset dispositions and other	4	5
Cash used in investing activities	(95)	(191)
FINANCING ACTIVITIES
Net transfers from (to) Parent	57	90
Payment on loan between subsidiaries	434
Intercompany dividends	(304)	(81)
Principal payments on debt	(2)	(2)
Other, net	(2)	(144)
Cash provided by (used in) financing activities	183	(137)
Effect of exchange rate changes on cash	(19)	(19)
Net increase (decrease) in cash and cash equivalents	217	(245)
Cash and cash equivalents at beginning of period	1,381	1,538
Cash and cash equivalents at end of period	$ 1,598	$ 1,293

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

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