Quarterly report pursuant to Section 13 or 15(d)

Asset Retirement Obligations - Changes to Asset Retirement Obligation (Details)

v3.21.2
Asset Retirement Obligations - Changes to Asset Retirement Obligation (Details) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Note 6 - Asset Retirement Obligations - Changes to Asset Retirement Obligation (Details)    
Balances, December 31, 2020 $ 392,704  
Liabilities settled (19,744)  
Accretion of discount 17,368  
Liabilities incurred and assumed through acquisition 417  
Revisions of estimated liabilities 17,129  
Balances, September 30, 2021 407,874  
Less current portion (27,545) $ (17,188)
Long-term $ 380,329 $ 375,516