Acquisitions, Consideration Paid (Details) - Dec. 31, 2014 - Alliance Boots [Member] £ in Millions, $ in Millions	USD ($)	GBP (£)
Consideration paid [Abstract]
Cash	$ 4,874	£ 3,133
Common stock	10,977
Total consideration transferred	15,851
Less: consideration attributed to WBAD	(2,559)
Total consideration after attributed amount to WBAD	13,292
Fair value of the investment in Alliance Boots held before the Second Step Transaction	8,149
Total consideration	$ 21,441

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
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Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination.

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Fair value at acquisition-date of the assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interests issued by the acquirer, including but not limited to, instruments or interests issued or issuable in consideration for the business combination.

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Fair value at acquisition-date of the equity interest in the acquiree held by the acquirer, immediately before the acquisition date for businesses combined in stages.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Amount of consideration transferred to acquiree, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount of net consideration after transferred to acquiree, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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