INTANGIBLE ASSETS AND GOODWILL (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Net Assets	$ 166,700
Amortization of Finite-Lived Intangible Assets	9,300	$ 9,300	$ 10,300
Amortizing Identifiable Intangible Assets [Abstract]
Gross	119,489	119,812
Accumulated Amortization	(115,057)	(106,130)
Net	4,432	13,682
Goodwill and intangible assets impairments [Abstract]
Goodwill	32,643	32,643
Future expected amortization expense, identifiable intangible assets
2017	4,400
2018	0
Completed technologies and patents [Member]
Amortizing Identifiable Intangible Assets [Abstract]
Gross	58,246	58,609
Accumulated Amortization	(54,508)	(47,072)
Net	3,738	11,537
Customer relationships [Member]
Amortizing Identifiable Intangible Assets [Abstract]
Gross	54,986	54,946
Accumulated Amortization	(54,292)	(52,801)
Net	694	2,145
Trade names [Member]
Amortizing Identifiable Intangible Assets [Abstract]
Gross	1,346	1,346
Accumulated Amortization	(1,346)	(1,346)
Net	0	0
Capitalized software costs [Member]
Amortizing Identifiable Intangible Assets [Abstract]
Gross	4,911	4,911
Accumulated Amortization	(4,911)	(4,911)
Net	$ 0	$ 0