REVENUE (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Segment Reporting, Revenue Reconciling Item [Line Items]
Number of Reportable Segments			1
Revenues	$ 93,461	$ 104,046	$ 295,481	$ 300,598
Subscription Arrangement [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	10,297	8,786	29,339	25,577
Nonsoftware Service, Support and Maintenance Arrangement [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	33,361	35,033	97,018	104,869
611710 Educational Support Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	6,892	8,094	21,491	25,230
Product [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	42,911	52,133	147,633	144,922
Service [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	50,550	51,913	147,848	155,676
Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	31,267	37,078	110,697	112,726
Other Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	9,471	7,466	23,232	20,216
Europe, Middle East and Africa [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	40,579	43,179	115,171	124,148
Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 12,144	$ 16,323	$ 46,381	$ 43,508