Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Feb. 29, 2020	Feb. 28, 2019
Operating Activities:
Net income	$ 1,620	$ 2,509
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	2,688	2,487
Asset impairment charges	66
Provision for uncollectible accounts	295	221
Stock-based compensation	137	141
Other noncash items and deferred income taxes	1,758	250
Changes in assets and liabilities:
Receivables	(504)	(780)
Other assets	(149)	(96)
Accounts payable and other liabilities	(2,612)	(1,307)
Other, net	(21)	(102)
Cash provided by operating activities	3,278	3,323
Investing Activities:
Capital expenditures	(4,705)	(3,757)
Proceeds from asset dispositions and other	15	62
Cash used in investing activities	(4,690)	(3,695)
Financing Activities:
Proceeds from short-term borrowings, net	298	220
Principal payments on debt	(1,045)	(874)
Proceeds from debt issuances	2,093	2,463
Proceeds from stock issuances	38	58
Dividends paid	(509)	(514)
Purchase of treasury stock	(3)	(1,365)
Other, net	(5)	5
Cash provided by (used in) financing activities	867	(7)
Effect of exchange rate changes on cash	(8)	(14)
Net decrease in cash and cash equivalents	(553)	(393)
Cash and cash equivalents at beginning of period	2,319	3,265
Cash and cash equivalents at end of period	$ 1,766	$ 2,872