Leases - Summary of Supplemental Balance Sheet and Other Information Related to Operating Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Non-current right-of-use assets	$ 3,068	$ 1,167
Right-of-use asset, Statement of financial position [Extensible List]	us-gaap:OtherAssets	us-gaap:OtherAssets
Current lease liabilities	$ 3,160	$ 564
Operating lease liability current, Statement of financial position [Extensible List]	Other current liabilities	Other current liabilities
Non-current lease liabilities	$ 57	$ 705
Operating lease liability noncurrent, Statement of financial position [Extensible List]	Other long-term liabilities	Other long-term liabilities
Weighted-average remaining lease term (in years)	1 year	2 years 1 month 6 days
Weighted-average discount rate	8.10%	9.60%