FAIR VALUE MEASUREMENTS (Details) (Recurring basis, USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Total fair value
Financial Assets
Total cash equivalents and short-term investments	$ 76,317	$ 125,622
Level 1
Financial Assets
Total cash equivalents and short-term investments	57,187	51,345
Level 1 | Treasury bills
Financial Assets
Total cash equivalents and short-term investments	5,403	17,722
Level 1 | Money market funds
Financial Assets
Total cash equivalents and short-term investments	51,784	33,623
Level 2
Financial Assets
Total cash equivalents and short-term investments	19,130	74,277
Level 2 | Corporate debentures/bonds
Financial Assets
Total cash equivalents and short-term investments	13,813	41,424
Level 2 | Commercial paper
Financial Assets
Total cash equivalents and short-term investments		6,193
Level 2 | Government agency bonds
Financial Assets
Total cash equivalents and short-term investments	$ 5,317	$ 26,660