Significant Accounting Policies - Lease Accounting (Details) $ in Millions	12 Months Ended
	Sep. 30, 2020 USD ($)
Leases [Line Items]
Lease extended term	five years
Selling, general and administrative expenses
Leases [Line Items]
Impairment on operating lease assets and lease hold improvements	$ 1.9
Minimum
Leases [Line Items]
Lease term	5 years
Maximum
Leases [Line Items]
Lease term	10 years