ACQUIRED INTANGIBLE ASSETS - Schedule of Acquired Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	$ 40,762	$ 38,105
Accumulated Amortization	(26,428)	(18,813)
Net	14,334	19,292
Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	1,285	1,285
Accumulated Amortization	(559)	(454)
Net	726	831
Technology Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	29,158	29,075
Accumulated Amortization	(21,329)	(14,702)
Net	7,829	14,373
Customer Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Cost	10,319	7,745
Accumulated Amortization	(4,540)	(3,657)
Net	$ 5,779	$ 4,088