Supplemental Guarantor Condensed Consolidating Financial Information, Statements of Cash Flows (Unaudited) (Details) - USD ($) $ in Millions	9 Months Ended
	May. 31, 2015	May. 31, 2014
Cash Flows from Operating Activities [Abstract]
Net cash provided by operating activities	$ 4,159	$ 2,509
Cash Flows from Investing Activities [Abstract]
Additions to property, plant and equipment	(890)	(821)
Proceeds from sale leaseback transactions	867	144
Proceeds related to the sale of business	814	0
Proceeds from sale of other assets	71	29
Alliance Boots acquisition, net of cash received	(4,461)	0
Other business and intangible asset acquisitions, net of cash received	(112)	(323)
Purchases of short-term investments held to maturity	(41)	(41)
Proceeds from short-term investments held to maturity	42	42
Investment in AmerisourceBergen	0	(493)
Other	(174)	(82)
Net cash used for investing activities	(3,884)	(1,545)
Cash Flows from Financing Activities [Abstract]
Payments of short-term borrowings, net	(251)	0
Proceeds from issuance of long-term debt	12,279	0
Payments of long-term debt	(8,582)	(550)
Proceeds from financing leases	0	225
Stock purchases	(831)	(205)
Proceeds related to employee stock plans	400	518
Cash dividends paid	(1,013)	(898)
Intra-company financing activities, net	0	0
Other	(380)	(34)
Net cash provided by (used for) financing activities	1,622	(944)
Effect of exchange rate changes on cash and cash equivalents	(94)	0
Changes in Cash and Cash Equivalents [Abstract]
Net increase in cash and cash equivalents	1,803	20
Cash and cash equivalents at beginning of period	2,646	2,106
Cash and cash equivalents at end of period	4,449	2,126
Guarantor Subsidiary [Member]
Cash Flows from Operating Activities [Abstract]
Net cash provided by operating activities	1,283	526
Cash Flows from Investing Activities [Abstract]
Additions to property, plant and equipment	(293)	(495)
Proceeds from sale leaseback transactions	420	121
Proceeds related to the sale of business	814
Proceeds from sale of other assets	35	52
Alliance Boots acquisition, net of cash received	0
Other business and intangible asset acquisitions, net of cash received	(62)	(280)
Purchases of short-term investments held to maturity	0	0
Proceeds from short-term investments held to maturity	0	0
Investment in AmerisourceBergen		0
Other	(174)	(4)
Net cash used for investing activities	740	(606)
Cash Flows from Financing Activities [Abstract]
Payments of short-term borrowings, net	(5)
Proceeds from issuance of long-term debt	0
Payments of long-term debt	(750)	(550)
Proceeds from financing leases		203
Stock purchases	(500)	(205)
Proceeds related to employee stock plans	154	518
Cash dividends paid	(642)	(898)
Intra-company financing activities, net	212	1,033
Other	(13)	(11)
Net cash provided by (used for) financing activities	(1,544)	90
Effect of exchange rate changes on cash and cash equivalents	0
Changes in Cash and Cash Equivalents [Abstract]
Net increase in cash and cash equivalents	479	10
Cash and cash equivalents at beginning of period	2,224	1,771
Cash and cash equivalents at end of period	2,703	1,781
Non-guarantor Subsidiaries [Member]
Cash Flows from Operating Activities [Abstract]
Net cash provided by operating activities	2,868	1,983
Cash Flows from Investing Activities [Abstract]
Additions to property, plant and equipment	(597)	(378)
Proceeds from sale leaseback transactions	447	23
Proceeds related to the sale of business	0
Proceeds from sale of other assets	36	29
Alliance Boots acquisition, net of cash received	0
Other business and intangible asset acquisitions, net of cash received	(50)	(43)
Purchases of short-term investments held to maturity	(41)	(41)
Proceeds from short-term investments held to maturity	42	42
Investment in AmerisourceBergen		(493)
Other	0	(78)
Net cash used for investing activities	(163)	(939)
Cash Flows from Financing Activities [Abstract]
Payments of short-term borrowings, net	(246)
Proceeds from issuance of long-term debt	0
Payments of long-term debt	(7,832)	0
Proceeds from financing leases		22
Stock purchases	0	0
Proceeds related to employee stock plans	0	0
Cash dividends paid	0	0
Intra-company financing activities, net	7,003	(1,033)
Other	(298)	(23)
Net cash provided by (used for) financing activities	(1,373)	(1,034)
Effect of exchange rate changes on cash and cash equivalents	(22)
Changes in Cash and Cash Equivalents [Abstract]
Net increase in cash and cash equivalents	1,310	10
Cash and cash equivalents at beginning of period	422	335
Cash and cash equivalents at end of period	1,732	345
Parent Company [Member]
Cash Flows from Operating Activities [Abstract]
Net cash provided by operating activities	8	0
Cash Flows from Investing Activities [Abstract]
Additions to property, plant and equipment	0	0
Proceeds from sale leaseback transactions	0	0
Proceeds related to the sale of business	0
Proceeds from sale of other assets	0	0
Alliance Boots acquisition, net of cash received	(4,461)
Other business and intangible asset acquisitions, net of cash received	0	0
Purchases of short-term investments held to maturity	0	0
Proceeds from short-term investments held to maturity	0	0
Investment in AmerisourceBergen		0
Other	0	0
Net cash used for investing activities	(4,461)	0
Cash Flows from Financing Activities [Abstract]
Payments of short-term borrowings, net	0
Proceeds from issuance of long-term debt	12,279
Payments of long-term debt	0	0
Proceeds from financing leases		0
Stock purchases	(331)	0
Proceeds related to employee stock plans	246	0
Cash dividends paid	(371)	0
Intra-company financing activities, net	(7,215)	0
Other	(69)	0
Net cash provided by (used for) financing activities	4,539	0
Effect of exchange rate changes on cash and cash equivalents	(72)
Changes in Cash and Cash Equivalents [Abstract]
Net increase in cash and cash equivalents	14	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	14	0
Consolidating Adjustments [Member]
Cash Flows from Operating Activities [Abstract]
Net cash provided by operating activities	0	0
Cash Flows from Investing Activities [Abstract]
Additions to property, plant and equipment	0	52
Proceeds from sale leaseback transactions	0	0
Proceeds related to the sale of business	0
Proceeds from sale of other assets	0	(52)
Alliance Boots acquisition, net of cash received	0
Other business and intangible asset acquisitions, net of cash received	0	0
Purchases of short-term investments held to maturity	0	0
Proceeds from short-term investments held to maturity	0	0
Investment in AmerisourceBergen		0
Other	0	0
Net cash used for investing activities	0	0
Cash Flows from Financing Activities [Abstract]
Payments of short-term borrowings, net	0
Proceeds from issuance of long-term debt	0
Payments of long-term debt	0	0
Proceeds from financing leases		0
Stock purchases	0	0
Proceeds related to employee stock plans	0	0
Cash dividends paid	0	0
Intra-company financing activities, net	0	0
Other	0	0
Net cash provided by (used for) financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	0
Changes in Cash and Cash Equivalents [Abstract]
Net increase in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	$ 0