Leases - Summary of Lease Term and Incremental Borrowing Rates for Leases (Details)	Jun. 30, 2021	Sep. 30, 2020
Weighted-average remaining lease term (in months):
Operating leases	50 months 15 days	55 months 27 days
Finance leases	50 months 3 days	55 months 24 days
Weighted-average discount rate:
Operating leases	6.80%	7.40%
Finance leases	4.40%	4.40%