The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35755396&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.12)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Equity Method Investments, Equity Method Investment (Details) - USD ($) $ in Millions	Aug. 31, 2015	Dec. 31, 2014	Aug. 31, 2014	Aug. 02, 2012
Schedule of Equity Method Investments [Line Items]
Carrying value	$ 0		$ 7,336
Alliance Boots [Member]
Schedule of Equity Method Investments [Line Items]
Carrying value			$ 7,336
Equity method investment ownership interest percentage		45.00%	45.00%	45.00%
Increased ownership percentage of Alliance Boots	100.00%
Other [Member]
Schedule of Equity Method Investments [Line Items]
Carrying value	$ 1,242		$ 74
Other [Member] \| Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership interest percentage	12.00%		30.00%
Other [Member] \| Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment ownership interest percentage	50.00%		50.00%
Total [Member]
Schedule of Equity Method Investments [Line Items]
Carrying value	$ 1,242		$ 7,410