Equity Method Investments (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		9 Months Ended
	Mar. 18, 2016	May 31, 2016	May 31, 2015	May 31, 2016	May 31, 2015
Schedule of Equity Method Investments [Line Items]
Equity earnings		$ 15	$ 7	$ 35	$ 15
AmerisourceBergen Corporation [Member]
Schedule of Equity Method Investments [Line Items]
Warrant issued to purchase common stock (in shares)	22,696,912
Warrant exercise price (in dollars per share)	$ 51.50
Warrants aggregate exercise price payment	$ 1,170
Outstanding shares owned (in shares)		34,157,955		34,157,955
Percentage of outstanding common shares owned		16.00%		16.00%
Other Investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings		$ 15	$ 7	$ 35	$ 15