PURCHASED INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Purchased intangible assets
Gross	$ 54,905	$ 54,796
Accumulated Amortization	(49,706)	(48,916)
Net	5,199	5,880
Core technology
Purchased intangible assets
Gross	17,098	17,717
Accumulated Amortization	(11,899)	(11,837)
Net	5,199	5,880
Customer relationships
Purchased intangible assets
Gross	35,865	35,091
Accumulated Amortization	(35,865)	(35,091)
Net	0	0
Trademarks / Trade names
Purchased intangible assets
Gross	1,942	1,988
Accumulated Amortization	(1,942)	(1,988)
Net	$ 0	$ 0