Consolidated Statements of Cash Flows (USD $) In Millions	12 Months Ended
	May 31, 2011	May 31, 2010	May 31, 2009
Operating Activities:
Net income	$ 1,452	$ 1,184	$ 98
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	1,973	1,958	1,975
Provision for uncollectible accounts	152	124	181
Deferred income taxes and other noncash items	669	331	299
Impairment and other charges	29	18	1,103
Stock-based compensation	98	101	99
Changes in assets and liabilities:
Receivables	(400)	(906)	762
Other assets	(114)	276	(196)
Pension assets and liabilities, net	(169)	(611)	(913)
Accounts payable and other liabilities	370	710	(628)
Other, net	(19)	(47)	(27)
Cash provided by operating activities	4,041	3,138	2,753
Investing Activities:
Capital expenditures	(3,434)	(2,816)	(2,459)
Business acquisition, net of cash acquired	(96)
Proceeds from asset dispositions and other	111	35	76
Cash used in investing activities	(3,419)	(2,781)	(2,383)
Financing Activities:
Principal payments on debt	(262)	(653)	(501)
Proceeds from debt issuance			1,000
Proceeds from stock issuances	108	94	41
Excess tax benefit on the exercise of stock options	23	25	4
Dividends paid	(151)	(138)	(137)
Other, net	(5)	(20)	(7)
Cash (used in) provided by financing activities	(287)	(692)	400
Effect of exchange rate changes on cash	41	(5)	(17)
Net increase (decrease) in cash and cash equivalents	376	(340)	753
Cash and cash equivalents at beginning of period	1,952	2,292	1,539
Cash and cash equivalents at end of period	$ 2,328	$ 1,952	$ 2,292