SHORT-TERM INVESTMENTS (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	$ 741,301	$ 743,892
Gross Unrealized Gain	1,329	769
Gross Unrealized Losses	(17)	(176)
Fair Value	742,613	744,485
Bank-time deposits
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	381,000	387,720
Gross Unrealized Gain	0	0
Gross Unrealized Losses	0	0
Fair Value	381,000	387,720
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	272,758	295,526
Gross Unrealized Gain	1,286	742
Gross Unrealized Losses	(17)	(127)
Fair Value	274,027	296,141
US Treasuries
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	28,898	55,656
Gross Unrealized Gain	43	27
Gross Unrealized Losses	0	(49)
Fair Value	28,941	55,634
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	58,645	4,990
Gross Unrealized Gain	0
Gross Unrealized Losses	0
Fair Value	$ 58,645	$ 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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-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
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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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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of 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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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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