SHORT-TERM INVESTMENTS - Schedule of Short-Term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	$ 1,440,460	$ 1,307,895
Gross Unrealized Gains	426	1,053
Gross Unrealized Losses	(255)	(256)
Fair Value	1,440,631	1,308,692
Bank-time deposits
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	577,741	578,762
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	577,741	578,762
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	706,959	520,486
Gross Unrealized Gains	411	994
Gross Unrealized Losses	(255)	(256)
Fair Value	707,115	521,224
US Treasuries
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	48,150	60,029
Gross Unrealized Gains	15	57
Gross Unrealized Losses	0	0
Fair Value	48,165	60,086
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	14	469
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Fair Value	14	470
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Cost or Amortized Cost	107,596	148,149
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Fair Value	$ 107,596	$ 148,150

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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