v3.26.1
Fair Value Measurements - Schedule of Financial Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Sep. 30, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]    
Cash equivalents, fair value $ 597,742 $ 642,997
Equity Securities, FV-NI 20,814 15,693
Equity Securities, FV-NI, Current 0 0
Equity Securities, FV-NI, Noncurrent 20,814 15,693
Investments, Fair Value Disclosure 618,556 658,690
Short-Term Investments 0 0
Long-Term Investments 20,814 15,693
Fair Value, Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]    
Equity Securities, FV-NI 20,814 15,693
Equity Securities, FV-NI, Current 0 0
Equity Securities, FV-NI, Noncurrent 20,814 15,693
Money Market Funds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]    
Cash equivalents, fair value 597,742 642,997
Money Market Funds | Fair Value, Recurring | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]    
Cash equivalents, fair value $ 597,742 $ 642,997