v3.22.2.2
Fair Value Measurements - Fair Value Measurements for Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($)
Sep. 30, 2022
Sep. 30, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Marketable debt securities $ 0 $ 126,728,000
Fair Value, Measurements, Recurring    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Marketable debt securities   126,728,000
Fair Value, Measurements, Recurring | Money market instruments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Money market instruments 39,262,000 160,032,000
Fair Value, Measurements, Recurring | U.S. government bonds    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 1,973,000  
Fair Value, Measurements, Recurring | Commercial notes    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 41,727,000  
Fair Value, Measurements, Recurring | Corporate debt securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 271,333,000 254,073,000
Fair Value, Measurements, Recurring | Certificate of deposits    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 50,000,000 50,000,000
Fair Value, Measurements, Recurring | Level 1    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Marketable debt securities   126,728,000
Fair Value, Measurements, Recurring | Level 1 | Money market instruments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Money market instruments 39,262,000 160,032,000
Fair Value, Measurements, Recurring | Level 1 | U.S. government bonds    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 1,973,000  
Fair Value, Measurements, Recurring | Level 1 | Commercial notes    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 0  
Fair Value, Measurements, Recurring | Level 1 | Corporate debt securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 0 0
Fair Value, Measurements, Recurring | Level 1 | Certificate of deposits    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 50,000,000 50,000,000
Fair Value, Measurements, Recurring | Level 2    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Marketable debt securities   0
Fair Value, Measurements, Recurring | Level 2 | Money market instruments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Money market instruments 0 0
Fair Value, Measurements, Recurring | Level 2 | U.S. government bonds    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 0  
Fair Value, Measurements, Recurring | Level 2 | Commercial notes    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 41,727,000  
Fair Value, Measurements, Recurring | Level 2 | Corporate debt securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 271,333,000 254,073,000
Fair Value, Measurements, Recurring | Level 2 | Certificate of deposits    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 0 0
Fair Value, Measurements, Recurring | Level 3    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Marketable debt securities   0
Fair Value, Measurements, Recurring | Level 3 | Money market instruments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Money market instruments 0 0
Fair Value, Measurements, Recurring | Level 3 | U.S. government bonds    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 0  
Fair Value, Measurements, Recurring | Level 3 | Commercial notes    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 0  
Fair Value, Measurements, Recurring | Level 3 | Corporate debt securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities 0 0
Fair Value, Measurements, Recurring | Level 3 | Certificate of deposits    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Held to maturity securities $ 0 $ 0