Condensed Consolidating Financial Statements (Details 4) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2015	Aug. 31, 2014
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	$ 1,241	$ 982
Investing Activities:
Capital expenditures	(1,209)	(720)
Proceeds from asset dispositions and other	10	4
Cash used in investing activities	(1,199)	(716)
Financing Activities:
Principal payments on debt	(15)
Proceeds from stock issuances	46	97
Excess tax benefit on the exercise of stock options	6	10
Dividends paid	(71)	(57)
Purchase of treasury stock	(190)	(791)
Cash used in financing activities	(224)	(741)
Effect of exchange rate changes on cash	(38)	(17)
Net decrease in cash and cash equivalents	(220)	(492)
Cash and cash equivalents at beginning of period	3,763	2,908
Cash and cash equivalents at end of period	3,543	2,416
Parent Company Member
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	(397)	(67)
Investing Activities:
Capital expenditures		(1)
Proceeds from asset dispositions and other	(5)
Cash used in investing activities	(5)	(1)
Financing Activities:
Net transfers from (to) Parent	452	358
Proceeds from stock issuances	46	97
Excess tax benefit on the exercise of stock options	6	10
Dividends paid	(71)	(57)
Purchase of treasury stock	(190)	(791)
Cash used in financing activities	243	(383)
Net decrease in cash and cash equivalents	(159)	(451)
Cash and cash equivalents at beginning of period	2,383	1,756
Cash and cash equivalents at end of period	2,224	1,305
Guarantor Subsidiaries Member
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	1,533	934
Investing Activities:
Capital expenditures	(1,170)	(688)
Proceeds from asset dispositions and other	15	7
Cash used in investing activities	(1,155)	(681)
Financing Activities:
Net transfers from (to) Parent	(479)	(366)
Payment on loan between subsidiaries	98	103
Intercompany dividends	4	2
Principal payments on debt	(2)
Other, net	(25)	(1)
Cash used in financing activities	(404)	(262)
Effect of exchange rate changes on cash	(15)	(2)
Net decrease in cash and cash equivalents	(41)	(11)
Cash and cash equivalents at beginning of period	487	441
Cash and cash equivalents at end of period	446	430
Non Guarantor Subsidiaries Member
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	71	105
Investing Activities:
Capital expenditures	(39)	(31)
Proceeds from asset dispositions and other		(3)
Cash used in investing activities	(39)	(34)
Financing Activities:
Net transfers from (to) Parent	27	8
Payment on loan between subsidiaries	(98)	(103)
Intercompany dividends	(4)	(2)
Principal payments on debt	(13)
Other, net	25	1
Cash used in financing activities	(63)	(96)
Effect of exchange rate changes on cash	(23)	(15)
Net decrease in cash and cash equivalents	(54)	(40)
Cash and cash equivalents at beginning of period	971	861
Cash and cash equivalents at end of period	917	821
Consolidation Eliminations Member
Condensed Financial Statements Captions [Line Items]
Cash provided by (used in) operating activities	34	10
Financing Activities:
Net decrease in cash and cash equivalents	34	10
Cash and cash equivalents at beginning of period	(78)	(150)
Cash and cash equivalents at end of period	$ (44)	$ (140)