Cash Equivalents and Marketable Securities - Available-for Sale Debt Securities by Contractual Maturity (Details) - Debt Securities, Available-For-Sale, Excluding Money Market Accounts - USD ($) $ in Thousands	Jul. 31, 2025	Apr. 30, 2025
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
AFS debt maturities, within one year, amortized cost	$ 481,267	$ 455,613
AFS debt maturities, after one year through five years, amortized cost	149,762	122,194
Amortized Cost	631,029	577,807
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
AFS debt maturities, within one year, fair value	481,387	455,956
AFS debt maturities, after one year through five years, fair value	149,570	122,374
AFS debt maturities, total fair value	$ 630,957	$ 578,330