ACQUIRED INTANGIBLE ASSETS - Schedule of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 114,499	$ 116,633
Accumulated Amortization	(45,420)	(39,531)
Net	69,079	77,102	$ 14,334	$ 19,292
Intangible technology assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	53,900	45,978
Accumulated Amortization	(31,873)	(28,420)
Net	22,027	17,558
Intangible customer assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	44,000	57,109
Accumulated Amortization	(6,934)	(8,068)
Net	37,066	49,041
Intangible trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	11,300	11,300
Accumulated Amortization	(4,473)	(1,648)
Net	6,827	9,652
Intangible other assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	5,299	2,246
Accumulated Amortization	(2,140)	(1,395)
Net	$ 3,159	$ 851