Acquisitions, Actual Results from Alliance Boots Operations Included in the Consolidated Condensed Statements of Earnings (Details) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Aug. 31, 2015 USD ($) $ / shares	May. 31, 2015 $ / shares	Feb. 28, 2015 $ / shares	Nov. 30, 2014 $ / shares	Aug. 31, 2014 USD ($) $ / shares	May. 31, 2014 $ / shares	Feb. 28, 2014 $ / shares	Nov. 30, 2013 $ / shares	Aug. 31, 2015 USD ($) $ / shares	Aug. 31, 2014 USD ($) $ / shares	Aug. 31, 2013 USD ($) $ / shares
Earnings Per Share [Abstract]
Basic (in dollars per share) | $ / shares	$ 0.02	$ 1.19	$ 1.96	$ 0.90	$ (0.23)	$ 0.75	$ 0.75	$ 0.76	$ 4.05	$ 2.03	$ 2.69
Diluted (in dollars per share) | $ / shares	$ 0.02	$ 1.18	$ 1.93	$ 0.89	$ (0.23)	$ 0.74	$ 0.74	$ 0.75	$ 4.00	$ 2.00	$ 2.67
Aggregate purchase price									$ 4,461	$ 0	$ 0
Goodwill									14,972	58
Alliance Boots [Member]
Business Acquisition [Line Items]
Net sales									22,470
Net earnings									$ 853
Earnings Per Share [Abstract]
Basic (in dollars per share) | $ / shares									$ 0.82
Diluted (in dollars per share) | $ / shares									$ 0.81
Goodwill									$ 14,800
Intangible assets	$ 11,691								11,691
Business combination, recognized identifiable assets acquired and liabilities assumed, net	6,592								6,592
Other Acquisitions and Divestitures [Member]
Earnings Per Share [Abstract]
Aggregate purchase price									371
Goodwill									126
Intangible assets	$ 255								255
Kerr Drug [Member]
Earnings Per Share [Abstract]
Goodwill									$ 42
Intangible assets					$ 54					54
Net cash paid					$ 170					$ 170
Number of stores acquired					76					76
Business combination, recognized identifiable assets acquired and liabilities assumed, net					$ 74					$ 74