INTANGIBLES AND GOODWILL - Composition of Intangible Assets (Details) - IPR&D intangible assets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Total Intangibles	$ 46,400	$ 46,400
United States | Vicinium
Finite-Lived Intangible Assets [Line Items]
Total Intangibles	31,700	31,700
Europe | Vicinium
Finite-Lived Intangible Assets [Line Items]
Total Intangibles	$ 14,700	$ 14,700