STOCK INCENTIVE PLANS AND SHARE-BASED COMPENSATION - Schedule of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Share-based compensation expense:
Total share-based compensation expense	$ 8,916	$ 11,583	$ 13,459
Cost of revenue
Share-based compensation expense:
Total share-based compensation expense	1,241	1,489	1,963
Research and development
Share-based compensation expense:
Total share-based compensation expense	1,864	2,559	3,430
Sales and marketing
Share-based compensation expense:
Total share-based compensation expense	2,907	3,506	4,097
General and administrative
Share-based compensation expense:
Total share-based compensation expense	$ 2,904	$ 4,029	$ 3,969