Summary of Significant Accounting Policies - ROU Assets and Lease Liability (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Accounting Policies [Abstract]
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other non-current assets, net	Other non-current assets, net
Right of use assets	$ 309	$ 700
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities	Other current liabilities
Current lease liability	$ 314	$ 392
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other non-current liabilities	Other non-current liabilities
Long-term lease liability	$ 0	$ 314