Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 31, 2020	Sep. 30, 2019
Commitments and Contingencies [Line Items]
Purchase obligation	$ 8.8	$ 4.4
Minimum
Commitments and Contingencies [Line Items]
Severance payment term	12 months
Maximum
Commitments and Contingencies [Line Items]
Severance payment term	36 months