Organization (Details) $ / shares in Units, £ in Millions, shares in Millions, $ in Billions			12 Months Ended
	Dec. 31, 2014 USD ($) Segment $ / shares shares	Dec. 31, 2014 GBP (£) Segment shares	Aug. 31, 2015 Segment $ / shares	Aug. 31, 2014 $ / shares
Schedule of Equity Method Investments [Line Items]
Number of reportable segment | Segment	3	3	3
Common stock, par value (in dollars per share) | $ / shares	$ 0.078125		$ 0.01	$ 0.078125
Total purchase price cash consideration	$ 4.9	£ 3,133
Walgreens Boots Alliance [Member]
Schedule of Equity Method Investments [Line Items]
Increased ownership percentage of Alliance Boots	55.00%
Total purchase price cash consideration		£ 3,133
Number of shares exchanged in acquisition (in shares) | shares	144.3	144.3