Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Nov. 30, 2019	Nov. 30, 2018
Operating Activities:
Net income	$ 1,305	$ 1,770
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	1,780	1,636
Asset impairment charges	66
Provision for uncollectible accounts	208	160
Stock-based compensation	104	108
Deferred income taxes and other noncash items	1,164	236
Changes in assets and liabilities:
Receivables	(684)	(1,343)
Other assets	(162)	(111)
Accounts payable and other liabilities	(1,691)	(227)
Other, net	(16)	(50)
Cash provided by operating activities	2,074	2,179
Investing Activities:
Capital expenditures	(3,266)	(2,634)
Proceeds from asset dispositions and other	4	53
Cash used in investing activities	(3,262)	(2,581)
Financing Activities:
Proceeds from short-term borrowings, net	150	248
Principal payments on debt	(1,021)	(785)
Proceeds from debt issuances	2,093	1,233
Proceeds from stock issuances	26	45
Dividends paid	(339)	(173)
Purchase of treasury stock	(3)	(1,271)
Other, net	(5)	1
Cash provided by (used in) financing activities	901	(702)
Effect of exchange rate changes on cash	(1)	(38)
Net decrease in cash and cash equivalents	(288)	(1,142)
Cash and cash equivalents at beginning of period	2,319	3,265
Cash and cash equivalents at end of period	$ 2,031	$ 2,123