Leases - Lease Term and Discount Rate (Details)	Sep. 30, 2021	Sep. 30, 2020
Lessee Disclosure [Abstract]
Weighted average remaining lease term, operating leases	4 years 9 months 18 days	4 years 8 months 12 days
Discount rate, operating leases (as a percent)	3.90%	4.10%
Weighted average remaining lease term, finance leases	8 years 1 month 6 days	2 years 10 months 24 days
Discount rate, finance leases (as a percent)	4.70%	5.40%