Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 31, 2012	May 31, 2011	May 31, 2010
Operating Activities:
Net income	$ 808	$ 731	$ 651
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	1,157	1,048	1,005
Provision for uncollectible accounts	117	117	75
Deferred income taxes and other noncash items	734	425	274
Noncash impairment charges	134
Changes in assets and liabilities:
Receivables	(194)	(138)	(369)
Other current assets	152	174	32
Accounts payable and other liabilities	16	270	444
Other, net	(5)	(6)	23
Cash provided by operating activities	2,919	2,621	2,135
Investing Activities:
Capital expenditures	(2,680)	(2,453)	(1,851)
Proceeds from asset dispositions and other	11	16	26
Business acquisitions, net of cash acquired	(116)	(96)
Cash used in investing activities	(2,785)	(2,533)	(1,825)
Financing Activities:
Principal payments on debt	(29)	(12)	(152)
Cash used in financing activities	(29)	(12)	(152)
Effect of exchange rate changes on cash	(19)	38	(6)
Net increase in cash and cash equivalents	86	114	152
Cash and cash equivalents at beginning of period	626	512	360
Cash and cash equivalents at end of period	$ 712	$ 626	$ 512