Investments - Available-for-Sale Marketable Securities (Details) - USD ($) $ in Thousands	Jul. 31, 2021	Apr. 30, 2021	Jul. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Cash equivalents	$ 273,779	$ 115,355	$ 128,979
Gross Unrealized Gains	200	101
Gross Unrealized Losses	(13)	(20)
Cash, cash equivalents and available-for-sale debt securities, amortized cost	1,006,472	1,021,340
Total cash equivalents and available-for-sale marketable securities	1,006,659	1,021,421
Money market funds
Debt Securities, Available-for-sale [Line Items]
Cash equivalents	175,998	43,401
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Cash equivalents	5,400	0
Amortized Cost	430,103	494,625
Gross Unrealized Gains	90	64
Gross Unrealized Losses	(2)	(13)
Estimated Fair Value	430,191	494,676
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Cash equivalents	50	0
Amortized Cost	24,164	2,369
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(8)	(1)
Estimated Fair Value	24,156	2,368
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,999	57,993
Gross Unrealized Gains	0	5
Gross Unrealized Losses	0	0
Estimated Fair Value	1,999	57,998
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	368,758	422,952
Gross Unrealized Gains	110	32
Gross Unrealized Losses	(3)	(6)
Estimated Fair Value	$ 368,865	$ 422,978

Cash, Cash Equivalents And Available-for-sale Debt Securities

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Cash, Cash Equivalents And Available-for-sale Debt Securities, Amortized Cost

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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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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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