REVENUES BY PRODUCT CATEGORY AND GEOGRAPHIC REGION AND SIGNIFICANT CONCENTRATIONS, Revenues By Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 67,918	$ 59,670	$ 58,854	$ 58,258	$ 58,200	$ 52,772	$ 58,552	$ 57,696	$ 244,700	$ 227,220	$ 218,901
North America [Member] | Reportable Geographical Components [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									194,660	181,853	175,019
Europe [Member] | Reportable Geographical Components [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									36,171	32,764	31,262
Asia Pacific and Rest of the World [Member] | Reportable Geographical Components [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									$ 13,869	$ 12,603	$ 12,620