REVENUES BY PRODUCT AND SERVICE CATEGORY AND GEOGRAPHIC REGION AND SIGNIFICANT CONCENTRATIONS, REVENUES BY GEOGRAPHIC REGION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Revenues from External Customers [Line Items]
Total revenues	$ 49,951	$ 49,802	$ 44,258	$ 42,014	$ 42,718	$ 37,850	$ 40,025	$ 36,003	$ 186,025	$ 156,596	$ 143,676
Worldwide Revenues [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of major customers									1	1	0
Revenue or accounts receivable by major customer (in hundredths)									11.00%	15.00%	10.00%
North America [Member]
Revenues from External Customers [Line Items]
Total revenues									152,774	128,969	117,992
Europe [Member]
Revenues from External Customers [Line Items]
Total revenues									26,086	21,926	20,308
Asia Pacific and Rest of the World [Member]
Revenues from External Customers [Line Items]
Total revenues									$ 7,165	$ 5,701	$ 5,376