Annual report pursuant to Section 13 and 15(d)

Asset Retirement Obligations - Schedule of Reconciliation of Asset Retirement Obligations (Details)

v3.23.3
Asset Retirement Obligations - Schedule of Reconciliation of Asset Retirement Obligations (Details) - USD ($)
$ in Thousands
12 Months Ended
Sep. 30, 2023
Sep. 30, 2022
Sep. 30, 2021
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]      
Balance at beginning of year $ 2,858 $ 2,788  
Liabilities incurred 0 0  
Liabilities settled (502) 0  
Liabilities assumed 0 0  
Accretion expense 61 70 $ 0
Balance at end of year $ 2,417 $ 2,858 $ 2,788