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Utility Plant and Intangible Assets 3 (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Reconciliation of the beginning and ending aggregate carrying amount of the asset retirement obligations    
Obligation at the beginning of the period $ 8,863 $ 5,228
Additional liabilities incurred 165 271
Liabilities settled (58) (173)
Accretion 350 86
Asset Retirement Obligation, Revision of Estimate   3,451
Obligation at the end of the period $ 9,320 $ 8,863
Wells and Related Equipment and Facilities [Member]    
Intangible assets    
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life 50 years