Annual report pursuant to Section 13 and 15(d)

Asset Retirement Obligations - Additional Information (Details)

v3.23.3
Asset Retirement Obligations - Additional Information (Details) - USD ($)
$ in Thousands
12 Months Ended
Sep. 30, 2023
Sep. 30, 2022
Sep. 30, 2021
Asset Retirement Obligation Disclosure [Abstract]      
Asset retirement obligation $ 2,417 $ 2,858 $ 2,788
Asset retirement obligation, accretion expense $ 61 $ 70 $ 0