Acquisitions (Details)	0 Months Ended		3 Months Ended		6 Months Ended					3 Months Ended	6 Months Ended			0 Months Ended	6 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2014 GBP (£)	Feb. 28, 2015 USD ($)	Feb. 28, 2014 USD ($)	Feb. 28, 2015 USD ($)	Feb. 28, 2014 USD ($)	Dec. 31, 2014	Dec. 30, 2014 USD ($)	Aug. 31, 2014 USD ($)	Feb. 28, 2015 Alliance Boots [Member] USD ($)	Feb. 28, 2015 Alliance Boots [Member] USD ($)	Dec. 31, 2014 Alliance Boots [Member]	Feb. 28, 2014 Alliance Boots [Member]	Jan. 01, 2015 Walgreens Boots Alliance Development GmbH [Member]	Feb. 28, 2015 Walgreens Boots Alliance Development GmbH [Member] USD ($)	Feb. 28, 2015 Other Acquisition [Member] USD ($)	Feb. 28, 2015 Retail Pharmacy International [Member] USD ($)	Feb. 28, 2015 Retail Pharmacy USA [Member] USD ($)	Feb. 28, 2015 Pharmaceutical Wholesale [Member] USD ($)
Business Acquisition [Line Items]
Business Acquisition, Percentage of issued and outstanding capital acquired (in hundredths)												55.00%
Equity method investment ownership interest percentage (in hundredths)			45.00%		45.00%					100.00%	100.00%	45.00%	45.00%		100.00%
Ownership interest percentage prior to Second Step Transaction															50.00%
Ownership interest percentage indirectly owned (in hundredths)															27.50%
Common shares sold (in shares)														320
Common shares transferred percentage (in hundredths)														5.00%
Equity method ownership option to repurchase shares, amount															$ 100,000
Noncontrolling interest (in hundredths)															27.50%
Noncontrolling interest acquired			212,000,000		212,000,000				104,000,000						2,600,000,000
Total purchase price	15,900,000,000				13,300,000,000						15,851,000,000
Total purchase price cash consideration	4,900,000,000	3,133,000,000									4,874,000,000
Spot rate							1.56
Purchase price consideration, common shares (in shares)	144,300,000	144,300,000
Purchase price consideration common shares fair value	11,000,000,000										8,290,000,000
Closing market price per share (in dollars per share)								$ 76.05
Gain on previously held equity interest	706,000,000		706,000,000	0	706,000,000	0
Fair value of previously held equity interest											8,300,000,000
Fair value of the assets acquired					3,700,000,000
Estimated manufacturing profit in acquired finished goods inventory capitalized			106,000,000		106,000,000					106,000,000	106,000,000
Aggregate purchase price					4,461,000,000	0										92,000,000
Intangible assets										11,461,000,000	11,461,000,000					64,000,000
Goodwill					15,579,000,000						15,556,000,000					23,000,000	3,747,000,000	8,311,000,000	3,521,000,000
Goodwill arising from synergies																		4,700,000,000
Goodwill based on a with and without analysis																		3,600,000,000
Selling, general and administrative expenses			$ 5,606,000,000	$ 4,569,000,000	$ 10,062,000,000	$ 8,948,000,000				$ 59,000,000	$ 83,000,000