Commitments and Contingencies - Leases and Asset Retirement Obligations Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Loss Contingencies [Line Items]
Lease option to extend length (in years)	5 years
Operating lease expenses	$ 3,700	$ 2,000
Impairment of Leasehold	1,400
Impairment charge	$ 22,612	$ 2,956
Risk-free rate, minimum	1.73%
Risk-free rate, maximum	4.03%
Minimum
Loss Contingencies [Line Items]
Operating lease, remaining lease term	1 year
Maximum
Loss Contingencies [Line Items]
Operating lease, remaining lease term	12 years