OTHER EXPENSE (INCOME), NET - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Other Income And Expenses [Line Items]
Favorable (unfavorable) adjustment, litigation and other matters	$ (1,401)	$ 27	$ (226)
Milestone achievement, included in net gain (loss) on other sales of assets	31	(6)	(37)
Upfront payments, included in acquired in-process research and development costs	41	1	5
Licensing Agreements
Schedule Of Other Income And Expenses [Line Items]
Upfront payments, included in acquired in-process research and development costs	38
Milestone Payment Related To Certain Product
Schedule Of Other Income And Expenses [Line Items]
Milestone achievement, included in net gain (loss) on other sales of assets	$ 20
Salix Ltd. SEC Investigation Litigation
Schedule Of Other Income And Expenses [Line Items]
Favorable (unfavorable) adjustment, litigation and other matters		$ 40
Allergan Shareholder Class Actions | Valeant Co Parties
Schedule Of Other Income And Expenses [Line Items]
Litigation and other matters			96
Solodyn Antitrust Class Actions
Schedule Of Other Income And Expenses [Line Items]
Litigation and other matters			93
Mimetogen Pharmaceuticals Litigation
Schedule Of Other Income And Expenses [Line Items]
Litigation and other matters			$ 20