Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Nov. 30, 2015	Nov. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (214)	$ 136
Other comprehensive income (loss) before reclassification adjustments	(451)	(122)
Amounts reclassified from accumulated OCI	1
Tax benefit (provision)	6	40
Net other comprehensive income (loss)	(444)	(82)
Ending Balance	(658)	54
Pension/Post-retirement Obligations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	29	15
Other comprehensive income (loss) before reclassification adjustments	3	(2)
Amounts reclassified from accumulated OCI	0
Tax benefit (provision)	0	1
Net other comprehensive income (loss)	3	(1)
Ending Balance	32	14
Unrecognized Gain (Loss) on Available-for-Sale Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	259	107
Other comprehensive income (loss) before reclassification adjustments	(5)	157
Amounts reclassified from accumulated OCI	0
Tax benefit (provision)	6	(58)
Net other comprehensive income (loss)	1	99
Ending Balance	260	206
Unrealized Gain (Loss) on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(40)	(27)
Other comprehensive income (loss) before reclassification adjustments	0	(20)
Amounts reclassified from accumulated OCI	1
Tax benefit (provision)	0	8
Net other comprehensive income (loss)	1	(12)
Ending Balance	(39)	(39)
Share of OCI of Alliance Boots [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(113)
Other comprehensive income (loss) before reclassification adjustments		32
Tax benefit (provision)		(11)
Net other comprehensive income (loss)		21
Ending Balance		(92)
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(462)	154
Other comprehensive income (loss) before reclassification adjustments	(449)	(289)
Amounts reclassified from accumulated OCI	0
Tax benefit (provision)	0	100
Net other comprehensive income (loss)	(449)	(189)
Ending Balance	$ (911)	$ 35