DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Summary of Effect of Foreign Exchange Forward Contracts on Other Comprehensive Income and Results of Operations (Details) - Forward contracts - Cash flow hedges - Designated as hedging instrument - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Loss Recognized in OCI on Derivative	$ (88)	$ (527)	$ (137)	$ (517)
Gain (Loss) Reclassified from Accumulated OCI into Income	(11)	468	11	1,790
Gain (Loss) Recognized in Income (Amount Excluded from Effectiveness Testing)	(39)	22	(61)	42
Research and development
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income	(6)	38	(18)	86
Gain (Loss) Recognized in Income (Amount Excluded from Effectiveness Testing)	18	29	31	63
Sales and marketing
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income	(5)	430	29	1,704
Gain (Loss) Recognized in Income (Amount Excluded from Effectiveness Testing)	$ (57)	$ (7)	$ (92)	$ (21)