REVENUE Revenue by Type (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Number of reportable segments			1
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 79,281	$ 98,701	$ 165,734	$ 202,020
Products and solutions net revenues
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	27,635		62,346
Subscription services
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	16,427	9,760	30,385	19,042
Support services
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	30,570	31,638	62,364	63,657
Professional services, training and other services
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 4,649	$ 6,977	$ 10,639	$ 14,599