COMMITMENTS AND CONTINGENCIES - Other Commitments, Narrative (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Apr. 30, 2015	Dec. 31, 2012	Mar. 31, 2010
Other commitments
Capital expenditures	$ 64,000,000
Milestone payments in terms of collaboration and license agreements, aggregate (up to)	1,150,000,000
B&L and Nicox
Other commitments
Potential milestone payments in terms of collaboration and license agreements (up to)					$ 145,000,000
US WorldMeds, LLC | Sales Based Milestone Payments
Other commitments
Potential milestone payments in terms of collaboration and license agreements (up to)	$ 335,000,000
Salix
Other commitments
Potential milestone payments in terms of collaboration and license agreements (up to)			$ 88,000,000
Brodalumab | Pre-launch Milestone Payments
Other commitments
Possible contingent consideration (up to)		$ 20,000,000
Brodalumab | Sales Based Milestone Payments
Other commitments
Possible contingent consideration (up to)		$ 175,000,000
Medicis Pharmaceutical Corporation | Regulatory, Commercialization and Sales-Based Milestone Payments
Other commitments
Possible contingent consideration (up to)				$ 111,000,000