Acquisitions, Divestitures, Research Collaborations and License Agreements - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Jan. 21, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill		$ 17,761	$ 12,992
Contingent consideration		614	$ 428	$ 75	$ 69
Cubist Pharmaceuticals Inc
Business Acquisition [Line Items]
Cash and cash equivalents	$ 733
Accounts receivable	123
Inventories	216
Other current assets	55
Property, plant and equipment	151
Products and product rights (11 year weighted-average useful life)	6,923
In-process research and development (IPR&D)	50
Other noncurrent assets	184
Current liabilities	(233)
Deferred income tax liabilities	(2,518)
Long-term debt	(1,900)
Other noncurrent liabilities	(122)
Total identifiable net assets	3,662
Goodwill	4,669
Consideration transferred	$ 8,331
Product and product rights, weighted average useful life	11 years
Contingent consideration		$ 123
Cubist Pharmaceuticals Inc | Other Current Liabilities
Business Acquisition [Line Items]
Contingent consideration	$ 73
Cubist Pharmaceuticals Inc | Other noncurrent liabilities
Business Acquisition [Line Items]
Contingent consideration	$ 50