Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Nov. 30, 2011	Nov. 30, 2010
Operating Activities:
Net income	$ 961	$ 663
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	1,027	981
Provision for uncollectible accounts	84	66
Stock-based compensation	60	56
Deferred income taxes and other noncash items	278	140
Changes in assets and liabilities:
Receivables	(291)	(79)
Other assets	(44)	(53)
Accounts payable and other liabilities	119	253
Other, net	(26)	(16)
Cash provided by operating activities	2,168	2,011
Investing Activities:
Capital expenditures	(2,217)	(2,059)
Business acquisition, net of cash acquired	(114)
Proceeds from asset dispositions and other	15	7
Cash used in investing activities	(2,316)	(2,052)
Financing Activities:
Principal payments on debt	(18)	(12)
Proceeds from stock issuances	32	25
Excess tax benefit on the exercise of stock options	5	4
Dividends paid	(82)	(76)
Purchase of treasury stock	(197)
Cash used in financing activities	(260)	(59)
Effect of exchange rate changes on cash	(24)	25
Net decrease in cash and cash equivalents	(432)	(75)
Cash and cash equivalents at beginning of period	2,328	1,952
Cash and cash equivalents at end of period	$ 1,896	$ 1,877