Leases - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Lessee, Lease, Description [Line Items]
Operating lease right of use asset non cash	$ 33.5	$ 33.5
Operating lease liability non cash	$ 10.1	$ 10.1
Minimum
Lessee, Lease, Description [Line Items]
Initial term of lease (in years)	3 years
Maximum
Lessee, Lease, Description [Line Items]
Initial term of lease (in years)	10 years