Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Oct. 31, 2023	Apr. 30, 2023
Available-for-sale marketable securities:
Total cash equivalents and available-for-sale marketable securities	$ 741,317	$ 717,717
Money market funds
Cash equivalents:
Estimated Fair Value	104,258	75,293
U.S. treasury securities
Cash equivalents:
Estimated Fair Value	1,989	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	4,921	27,397
Certificates of deposit
Cash equivalents:
Estimated Fair Value	0	2,000
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	69,547	61,025
Commercial paper
Cash equivalents:
Estimated Fair Value	21,810	112,851
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	228,509	184,230
U.S. government agencies securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	58,564	75,674
Yankee bonds
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	2,239	0
Corporate debt securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	249,480	179,247
Fair Value, Recurring
Available-for-sale marketable securities:
Total cash equivalents and available-for-sale marketable securities	741,317	717,717
Fair Value, Recurring | Money market funds
Cash equivalents:
Estimated Fair Value	104,258	75,293
Fair Value, Recurring | U.S. treasury securities
Cash equivalents:
Estimated Fair Value	1,989	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	4,921	27,397
Fair Value, Recurring | Certificates of deposit
Cash equivalents:
Estimated Fair Value	0	2,000
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	69,547	61,025
Fair Value, Recurring | Commercial paper
Cash equivalents:
Estimated Fair Value	21,810	112,851
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	228,509	184,230
Fair Value, Recurring | U.S. government agencies securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	58,564	75,674
Fair Value, Recurring | Yankee bonds
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	2,239	0
Fair Value, Recurring | Corporate debt securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	249,480	179,247
Fair Value, Recurring | Level 1
Available-for-sale marketable securities:
Total cash equivalents and available-for-sale marketable securities	104,258	75,293
Fair Value, Recurring | Level 1 | Money market funds
Cash equivalents:
Estimated Fair Value	104,258	75,293
Fair Value, Recurring | Level 1 | U.S. treasury securities
Cash equivalents:
Estimated Fair Value	0	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 1 | Certificates of deposit
Cash equivalents:
Estimated Fair Value	0	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 1 | Commercial paper
Cash equivalents:
Estimated Fair Value	0	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 1 | U.S. government agencies securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 1 | Yankee bonds
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 1 | Corporate debt securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 2
Available-for-sale marketable securities:
Total cash equivalents and available-for-sale marketable securities	637,059	642,424
Fair Value, Recurring | Level 2 | Money market funds
Cash equivalents:
Estimated Fair Value	0	0
Fair Value, Recurring | Level 2 | U.S. treasury securities
Cash equivalents:
Estimated Fair Value	1,989	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	4,921	27,397
Fair Value, Recurring | Level 2 | Certificates of deposit
Cash equivalents:
Estimated Fair Value	0	2,000
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	69,547	61,025
Fair Value, Recurring | Level 2 | Commercial paper
Cash equivalents:
Estimated Fair Value	21,810	112,851
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	228,509	184,230
Fair Value, Recurring | Level 2 | U.S. government agencies securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	58,564	75,674
Fair Value, Recurring | Level 2 | Yankee bonds
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	2,239	0
Fair Value, Recurring | Level 2 | Corporate debt securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	249,480	179,247
Fair Value, Recurring | Level 3
Available-for-sale marketable securities:
Total cash equivalents and available-for-sale marketable securities	0	0
Fair Value, Recurring | Level 3 | Money market funds
Cash equivalents:
Estimated Fair Value	0	0
Fair Value, Recurring | Level 3 | U.S. treasury securities
Cash equivalents:
Estimated Fair Value	0	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 3 | Certificates of deposit
Cash equivalents:
Estimated Fair Value	0	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 3 | Commercial paper
Cash equivalents:
Estimated Fair Value	0	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 3 | U.S. government agencies securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 3 | Yankee bonds
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 3 | Corporate debt securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	$ 0	$ 0