Fair Value Measurements - Debt Securities, Available-for-sale (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Mar. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 372,389	$ 566,289
Unrealized Gains	0	79
Unrealized Losses	(10,125)	(6,384)
Total	362,264	559,984
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	52,000	127,500
Unrealized Gains	0	0
Unrealized Losses	(354)	(615)
Total	51,646	126,885
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,953	27,946
Unrealized Gains	0	0
Unrealized Losses	(27)	(85)
Total	2,926	27,861
Corporate notes and bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	86,193	87,259
Unrealized Gains	0	0
Unrealized Losses	(3,458)	(2,194)
Total	82,735	85,065
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	231,243	323,584
Unrealized Gains	0	79
Unrealized Losses	(6,286)	(3,490)
Total	$ 224,957	$ 320,173

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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Amortized cost 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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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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