Leases - Additional information related to leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 6,964	$ 6,101
Operating cash flows from finance leases	925	973
Financing cash flows from finance leases	1,331	1,224
Right-of-use assets obtained in exchange for operating lease liabilities
Operating leases	$ 16,243	$ 4,160
Weighted-average remaining lease term:
Operating leases	11 years 1 month 6 days	9 years 3 months 18 days
Finance leases	11 years 1 month 6 days	12 years
Weighted-average discount rate:
Operating leases	4.50%	3.20%
Finance leases	4.60%	4.60%