DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Summary of Effect of Foreign Exchange Forward Contracts on Other Comprehensive Income and Results of Operations (Details) - Forward contracts - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Loss Recognized in OCI on Derivative	$ (27)		$ (101)
Loss Recognized in OCI on Derivative		$ (59)		$ (578)
Gain (Loss) Reclassified from Accumulated OCI into Income	24		70
Research and development
Derivative Instruments, Gain (Loss) [Line Items]
Loss Recognized in OCI on Derivative	(27)		(101)
Loss Recognized in OCI on Derivative		(59)		(578)
Gain (Loss) Reclassified from Accumulated OCI into Income	(4)		(8)
Sales and marketing
Derivative Instruments, Gain (Loss) [Line Items]
Loss Recognized in OCI on Derivative
Loss Recognized in OCI on Derivative
Gain (Loss) Reclassified from Accumulated OCI into Income	$ 28		$ 78
Cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income		202		296
Cash flow hedges | Research and development
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income		57		87
Cash flow hedges | Sales and marketing
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income		$ 145		$ 209