Capital Stock (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2014
Equity, Class of Treasury Stock [Line Items]
Stock repurchased during current fiscal year, value	$ 1,000	$ 500	$ 705
Shares of common stock reserved for future issuances (in shares)	43.8
2014 Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Purchase of shares under stock repurchase program (in shares)	1.3	8.2
Value of shares purchased under stock repurchase program	$ 110	$ 726
Common Stock [Member] | 2014 Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized maximum amount	$ 3,000