Leases - Summary of Weighted-average Remaining Lease Terms and Incremental Borrowing Rates (Details)	Sep. 30, 2021	Sep. 30, 2020
Operating leases:
Weighted-average remaining lease term (years)	4 years 10 months 24 days	5 years 4 months 24 days
Weighted-average incremental borrowing rate	3.30%	3.30%
Finance leases:
Weighted-average remaining lease term (years)	2 years 8 months 12 days	2 years 4 months 24 days
Weighted-average incremental borrowing rate	3.30%	3.30%