Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Apr. 30, 2024	Apr. 30, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 53,521	$ 81,352
Marketable securities	0	16,632
Total	77,782	105,289
US Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury securities	24,261	7,305
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	53,521	81,352
Marketable securities	0	16,632
Total	77,782	105,289
Quoted Prices in Active Markets for Identical Assets (Level 1) | US Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury securities	24,261	7,305
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Marketable securities	0	0
Total	0	0
Significant Other Observable Inputs (Level 2) | US Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury securities	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Marketable securities	0	0
Total	0	0
Significant Unobservable Inputs (Level 3) | US Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasury securities	$ 0	$ 0