Available-for-Sale Investments (Details) - USD ($) $ in Millions	3 Months Ended
	Nov. 30, 2015	Aug. 31, 2015
Summary of cost and fair value of available-for-sale securities [Abstract]
Cost	$ 752	$ 754
Gross unrealized gains	414	430
Gross unrealized losses	(2)	(1)
Fair value	1,164	1,183
Available for sale securities, current	$ 33
AmerisourceBergen Common Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Maximum number of shares in minority equity position	19,859,795
Percentage of outstanding common stock held	5.20%
Sale of acquired available-for-sale securities	$ 2
Number of shares held (in shares)	11,500,000
Summary of cost and fair value of available-for-sale securities [Abstract]
Cost	$ 717	717
Gross unrealized gains	414	430
Gross unrealized losses	0	0
Fair value	1,131	1,147
Other Investments [Member]
Summary of cost and fair value of available-for-sale securities [Abstract]
Cost	35	37
Gross unrealized gains	0	0
Gross unrealized losses	(2)	(1)
Fair value	$ 33	$ 36