Acquisitions, Divestitures, Assets and Liabilities Held for Sale, Licensing Arrangements, Research and Development and Collaborative Arrangements, Equity-Method Investments and Privately Held Investment - Anacor Pharmaceuticals, Inc. (Details) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
		Jun. 24, 2016	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Business Acquisition [Line Items]
Cash payments for acquisition, net of cash acquired	[1]		$ 0		$ 1,000		$ 18,368
Goodwill			$ 53,411	[2]	$ 55,952	[2]	$ 54,449
Anacor [Member]
Business Acquisition [Line Items]
Business acquisition, per share in cash (in dollars per share)		$ 99.25
Payments to acquire businesses, cash portion		$ 4,900
Cash payments for acquisition, net of cash acquired		4,500
Debt assumed		698
Indefinite-lived intangible assets		4,900
Goodwill		646
Net deferred tax liabilities		346
In Process Research and Development [Member] | Anacor [Member]
Business Acquisition [Line Items]
Intangible assets		$ 4,800

[1] Amounts may not add due to rounding.

[2] Amounts may not add due to rounding.