v3.26.1
Fair Value Measurements (Tables)
 6 Months Ended
Mar. 31, 2026
Fair Value Disclosures [Abstract]  
Schedule of Financial Assets Measured at Fair Value on a Recurring Basis
The Company's financial assets measured at fair value on a recurring basis at March 31, 2026 and September 30, 2025, were as follows (in thousands):
  Gross Unrealized Classification on Balance Sheet
March 31, 2026Fair Value Level Cost or Amortized Cost Gains Losses Aggregate
Fair Value		Cash and Cash Equivalents Short-Term Investments Long-Term Investments
Changes in fair value recorded in other comprehensive income (loss):
Money market fundsLevel 1$597,742 $— $— $597,742 $597,742 $— $— 
Total cash equivalents$597,742 $— $— $597,742 $597,742 $— $— 
Changes in fair value recorded in other net income (expense):
Equity investments*$20,814 $— $— $20,814 
Total equity investments20,814 — — 20,814 
Total$618,556 $597,742 $— $20,814 
* Equity investments presented in the table above include investments without readily determinable fair values that are measured at fair value using net asset value ("NAV") as a practical expedient, or are measured at cost with adjustments for observable changes in price or impairments. The equity investments are not classified within the fair value hierarchy.
  Gross Unrealized Classification on Balance Sheet
September 30, 2025Fair Value LevelCost or Amortized Cost Gains Losses Aggregate
Fair Value		Cash and Cash Equivalents Short-Term Investments Long-Term Investments
Changes in fair value recorded in other comprehensive income (loss):
Money market fundsLevel 1$642,997 $— $— $642,997 $642,997 $— $— 
Total cash equivalents$642,997 $— $— $642,997 $642,997 $— $— 
Changes in fair value recorded in other net income (expense):
Equity investments*$15,693 $— $— $15,693 
Total equity investments15,693 — — 15,693 
Total$658,690 $642,997 $— $15,693 
* Equity investments presented in the table above include investments without readily determinable fair values that are measured at fair value using NAV as a practical expedient, or are measured at cost with adjustments for observable changes in price or impairments. The equity investments are not classified within the fair value hierarchy.