Licensing, Acquisitions, and Other Arrangements - Other Licensing & Acquisitions Activity (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Licensing, Acquisitions, and Other Arrangements
Cash outflows related to acquisitions and investments	$ 12	$ 320
Acquired in-process research and development	$ 0	$ 155

The amount of the write-off for research and development assets that were acquired in a transaction other than a business combination.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

Name:	us-gaap_ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration