v3.23.1
Fair value measurement - Cash And Cash Equivalents And Available For Sale Securities At Fair Value (Details) - USD ($)
$ in Thousands
Sep. 30, 2022
Sep. 30, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash and cash equivalents $ 378,687 $ 465,829
Amortized cost 506,562 477,862
Gross unrealized gains 0 1
Gross unrealized losses (1,594) 0
Cash and cash equivalents, fair value 378,687 465,829
Fair value 504,968 477,863
Commercial paper    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Short term investments, Amortized cost 14,997  
Gross unrealized gains 0  
Gross unrealized losses 0  
Short term investments, fair value 14,997  
U.S. government treasury bills    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Short term investments, Amortized cost 112,878 12,033
Gross unrealized gains 0 1
Gross unrealized losses (1,594) 0
Short term investments, fair value $ 111,284 $ 12,034