Condensed Consolidating Financial Statements (Details 4) - USD ($) $ in Millions	12 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2013
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	$ 5,366	$ 4,264	$ 4,688
Investing Activities:
Capital expenditures	(4,347)	(3,533)	(3,375)
Business acquisitions, net of cash acquired	(1,429)	(36)	(483)
Proceeds from asset dispositions and other	24	18	55
Cash used in investing activities	(5,752)	(3,551)	(3,803)
Financing Activities:
Principal payments on debt	(5)	(254)	(417)
Proceeds from debt issuance	2,491	1,997	1,739
Proceeds from stock issuances	320	557	280
Excess tax benefit on the exercise of stock options	51	44	23
Dividends paid	(227)	(187)	(177)
Purchase of treasury stock, including accelerated share repurchase agreements	(1,254)	(4,857)	(246)
Other, net	(27)	(19)	(18)
Cash provided by (used in) financing activities	1,349	(2,719)	1,184
Effect of exchange rate changes on cash	(108)	(3)	5
Net increase (decrease) in cash and cash equivalents	855	(2,009)	2,074
Cash and cash equivalents at beginning of period	2,908	4,917	2,843
Cash and cash equivalents at end of period	3,763	2,908	4,917
Parent Company [Member]
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	(727)	(8)	247
Investing Activities:
Capital expenditures	(1)	(1)	(3)
Business acquisitions, net of cash acquired	(1,429)
Cash used in investing activities	(1,430)	(1)	(3)
Financing Activities:
Net transfers from (to) Parent	1,431	588	141
Principal payments on debt		(250)
Proceeds from debt issuance	2,491	1,997	1,739
Proceeds from stock issuances	320	557	280
Excess tax benefit on the exercise of stock options	51	44	23
Dividends paid	(227)	(187)	(177)
Purchase of treasury stock, including accelerated share repurchase agreements	(1,254)	(4,857)	(246)
Other, net	(27)	(19)	(18)
Cash provided by (used in) financing activities	2,785	(2,127)	1,742
Effect of exchange rate changes on cash	(1)
Net increase (decrease) in cash and cash equivalents	627	(2,136)	1,986
Cash and cash equivalents at beginning of period	1,756	3,892	1,906
Cash and cash equivalents at end of period	2,383	1,756	3,892
Guarantor Subsidiaries [Member]
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	5,446	3,790	3,936
Investing Activities:
Capital expenditures	(4,139)	(3,230)	(3,029)
Business acquisitions, net of cash acquired		(36)
Proceeds from asset dispositions and other	42	37	49
Cash used in investing activities	(4,097)	(3,229)	(2,980)
Financing Activities:
Net transfers from (to) Parent	(1,502)	(546)	(58)
Payment on loan between subsidiaries	267	(4)	(385)
Intercompany dividends	68	54	21
Principal payments on debt	(1)	(4)	(417)
Other, net	(105)	(16)	(119)
Cash provided by (used in) financing activities	(1,273)	(516)	(958)
Effect of exchange rate changes on cash	(30)	(9)	(10)
Net increase (decrease) in cash and cash equivalents	46	36	(12)
Cash and cash equivalents at beginning of period	441	405	417
Cash and cash equivalents at end of period	487	441	405
Non Guarantor Subsidiaries [Member]
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	575	535	486
Investing Activities:
Capital expenditures	(207)	(302)	(343)
Business acquisitions, net of cash acquired			(483)
Proceeds from asset dispositions and other	(18)	(19)	6
Cash used in investing activities	(225)	(321)	(820)
Financing Activities:
Net transfers from (to) Parent	71	(42)	(83)
Payment on loan between subsidiaries	(267)	4	385
Intercompany dividends	(68)	(54)	(21)
Principal payments on debt	(4)
Other, net	105	16	119
Cash provided by (used in) financing activities	(163)	(76)	400
Effect of exchange rate changes on cash	(77)	6	15
Net increase (decrease) in cash and cash equivalents	110	144	81
Cash and cash equivalents at beginning of period	861	717	636
Cash and cash equivalents at end of period	971	861	717
Consolidation Eliminations [Member]
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	72	(53)	19
Financing Activities:
Net increase (decrease) in cash and cash equivalents	72	(53)	19
Cash and cash equivalents at beginning of period	(150)	(97)	(116)
Cash and cash equivalents at end of period	$ (78)	$ (150)	$ (97)