Equity Method Investments (Details) Share data in Millions, unless otherwise specified	3 Months Ended			3 Months Ended		3 Months Ended
	Nov. 30, 2014 USD ($)	Nov. 30, 2013 USD ($)	Aug. 31, 2014 USD ($)	Nov. 30, 2014 Alliance Boots [Member] USD ($)	Nov. 30, 2014 Alliance Boots [Member] GBP (£)	Nov. 30, 2014 UniDrug Distribution [Member] USD ($)	Nov. 30, 2014 UniDrug Distribution [Member] GBP (£)
Schedule of Equity Method Investments [Line Items]
Cash paid to acquire investment				$ 4,025,000,000
Gain recognized on acquisition						23,000,000	32,000,000
Shares issued for Investment in Alliance Boots (in shares)				83.4
Remaining ownership subject to call option (in hundredths)				55.00%
Remaining percentage acquired (in hundredths)						50.00%	50.00%
Cash price to exercise call option				4,900,000,000	3,100,000,000
Shares to be issued upon exercise of call option (in shares)				144.3
Reduced ownership percentage if call option is not exercised (in hundredths)				42.00%
Impact of change in tax law		71,000,000
Non-controlling interests	283,000,000	378,000,000	257,000,000
Translation rate (1 GBP to USD)	1.66	1.55	1.68
Translation rate for reporting period (1 GBP to USD)	1.68	1.53
Goodwill subject to impairment in an equity method investee					248,000,000
Company's share of goodwill subject to impairment in an equity method investee				$ 185,000,000	£ 112,000,000