Leases - Narrative (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2023 USD ($) sublease_option sublease	Sep. 30, 2022 USD ($)
Leases [Abstract]
Impairment loss of long-lived asset | $	$ 7,673	$ 0
Number of subleased facilities | sublease	1
Sublease term	5 years
Number of sublease extension options | sublease_option	2
Sublease option extension period	1 year
Weighted-average remaining lease term	6 years 3 months 18 days
Weighted-average discount rate	6.30%