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Utility Plant and Intangible Assets 3 (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Reconciliation of the beginning and ending aggregate carrying amount of the asset retirement obligations    
Obligation at the beginning of the period $ 5,228 $ 4,963
Additional liabilities incurred 271 256
Liabilities settled (173) (46)
Accretion 86 55
Asset Retirement Obligation, Revision of Estimate 3,451  
Obligation at the end of the period $ 8,863 $ 5,228
Wells and Related Equipment and Facilities [Member]    
Intangible assets    
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life 50 years