SHORT-TERM INVESTMENTS (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015
Short-term investments
Cost or Amortized Cost	$ 375,079	$ 186,954
Gross Unrealized Gains	17	39
Gross Unrealized Losses	(83)	(64)
Fair Value	375,013	186,929
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity
Due in 1 year or less	338,459
Due in 1-2 years	36,620
Total amortized cost	375,079
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity
Due in 1 year or less	338,433
Due in 1-2 years	36,580
Total fair value	375,013
Bank time deposits
Short-term investments
Cost or Amortized Cost	275,140	87,500
Fair Value	275,140	87,500
Corporate bonds
Short-term investments
Cost or Amortized Cost	99,939	99,454
Gross Unrealized Gains	17	39
Gross Unrealized Losses	(83)	(64)
Fair Value	$ 99,873	$ 99,429