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Asset Retirement Obligations - Asset Retirement Obligations Table (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
Carrying amount of asset retirement obligations at beginning of year $ 280,498 $ 358,868
Liabilities incurred 23,923 9,565
Liabilities settled (12,710) (20,418)
Accretion expense 12,664 15,070
Revisions in estimated liabilities 3,834 (82,587)
Carrying amount of asset retirement obligations at end of year $ 308,209 $ 280,498