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Unevaluated Property (Details Textuals)
12 Months Ended
Dec. 31, 2019
Minimum  
Capitalized Costs of Unproved Properties Excluded from Amortization  
Anticipated Timing of Inclusion of Costs in Amortization Calculation 5 years
Maximum  
Capitalized Costs of Unproved Properties Excluded from Amortization  
Anticipated Timing of Inclusion of Costs in Amortization Calculation 10 years