SHORT-TERM INVESTMENTS (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Cost or Amortized Cost	$ 646,786	$ 743,892
Gains	645	769
Losses	(3,428)	(176)
Fair Value	644,003	744,485
Bank time deposits
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Cost or Amortized Cost	191,000	387,720
Gains	0	0
Losses	0	0
Fair Value	191,000	387,720
Corporate bonds
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Cost or Amortized Cost	337,752	295,526
Gains	307	742
Losses	(3,428)	(127)
Fair Value	334,631	296,141
US Treasuries
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Cost or Amortized Cost	30,481	55,656
Gains	338	27
Losses	0	(49)
Fair Value	30,819	55,634
Commercial paper
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Cost or Amortized Cost	87,553	4,990
Gains	0	0
Losses	0	0
Fair Value	$ 87,553	$ 4,990

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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