Leases - Components of Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Lease Assets and Liabilities
Right-of-use assets	$ 58,291	$ 17,346
Lease liabilities	2,776	2,250
Lease liabilities, net of current portion	78,800	23,295
Lease Cost
Total	9,763	5,962	$ 3,201
Research and development
Lease Cost
Operating lease cost	7,278	3,649	925
Variable lease cost	728	814	802
General and administrative expense
Lease Cost
Operating lease cost	1,757	1,498	1,474
Variable lease cost	$ 0	$ 1	$ 0

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Amount of lease cost recognized by lessee for lease contract.

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Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.

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Amount of lessee's right to use underlying asset under operating lease.

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Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

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