Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jan. 31, 2023	Apr. 30, 2022
Available-for-sale marketable securities:
Total cash equivalents and available-for-sale marketable securities	$ 759,465	$ 914,840
Money market funds
Cash equivalents:
Estimated Fair Value	155,476	107,726
Certificates of deposit
Cash equivalents:
Estimated Fair Value	0	3,000
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	64,252	97,205
U.S. treasury securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	12,442	12,763
U.S. government agencies securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	26,428	13,890
Commercial paper
Cash equivalents:
Estimated Fair Value	121,995	142,511
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	180,413	241,132
Corporate debt securities
Cash equivalents:
Estimated Fair Value	3,327	8,884
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	195,132	287,729
Fair Value, Recurring
Available-for-sale marketable securities:
Total cash equivalents and available-for-sale marketable securities	759,465	914,840
Fair Value, Recurring | Money market funds
Cash equivalents:
Estimated Fair Value	155,476	107,726
Fair Value, Recurring | Certificates of deposit
Cash equivalents:
Estimated Fair Value	0	3,000
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	64,252	97,205
Fair Value, Recurring | U.S. treasury securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	12,442	12,763
Fair Value, Recurring | U.S. government agencies securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	26,428	13,890
Fair Value, Recurring | Commercial paper
Cash equivalents:
Estimated Fair Value	121,995	142,511
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	180,413	241,132
Fair Value, Recurring | Corporate debt securities
Cash equivalents:
Estimated Fair Value	3,327	8,884
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	195,132	287,729
Fair Value, Recurring | Level 1
Available-for-sale marketable securities:
Total cash equivalents and available-for-sale marketable securities	155,476	107,726
Fair Value, Recurring | Level 1 | Money market funds
Cash equivalents:
Estimated Fair Value	155,476	107,726
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 | U.S. treasury securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value		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 | Commercial paper
Cash equivalents:
Estimated Fair Value		0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	0	0
Fair Value, Recurring | Level 1 | Corporate debt 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 2
Available-for-sale marketable securities:
Total cash equivalents and available-for-sale marketable securities	603,989	807,114
Fair Value, Recurring | Level 2 | Money market funds
Cash equivalents:
Estimated Fair Value	0	0
Fair Value, Recurring | Level 2 | Certificates of deposit
Cash equivalents:
Estimated Fair Value	0	3,000
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	64,252	97,205
Fair Value, Recurring | Level 2 | U.S. treasury securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	12,442	12,763
Fair Value, Recurring | Level 2 | U.S. government agencies securities
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	26,428	13,890
Fair Value, Recurring | Level 2 | Commercial paper
Cash equivalents:
Estimated Fair Value	121,995	142,511
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	180,413	241,132
Fair Value, Recurring | Level 2 | Corporate debt securities
Cash equivalents:
Estimated Fair Value	3,327	8,884
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	195,132	287,729
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 | 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 | U.S. treasury securities
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 | 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 | Corporate debt securities
Cash equivalents:
Estimated Fair Value	0	0
Available-for-sale marketable securities:
Available-for-sale marketable securities, fair value	$ 0	$ 0