Quarterly report pursuant to Section 13 or 15(d)

EQUITY INVESTMENTS (Narrative) (Details)

v3.20.2
EQUITY INVESTMENTS (Narrative) (Details)
$ / shares in Units, a in Thousands
 1 Months Ended 3 Months Ended 6 Months Ended
May 31, 2019
$ / shares
Feb. 28, 2019
$ / shares
Jun. 30, 2020
USD ($)
shares
Jun. 30, 2019
USD ($)
Jun. 30, 2020
USD ($)
a
shares
Jun. 30, 2019
USD ($)
Dec. 31, 2019
USD ($)
Schedule of Equity Method Investments [Line Items]              
Equity investments     $ 13,052,000   $ 13,052,000   $ 32,044,000
Investment in Mammoth Energy Services, Inc.              
Schedule of Equity Method Investments [Line Items]              
Equity method investment, ownership (in shares) | shares     9,829,548   9,829,548    
Approximate fair value, quoted market price     $ 11,600,000   $ 11,600,000    
Share dividend (in usd per share) | $ / shares $ 0.125 $ 0.125          
Investment in Grizzly Oil Sands ULC              
Schedule of Equity Method Investments [Line Items]              
Equity method investment, ownership interest, percent     24.60%   24.60%    
Equity method investment, impairment         $ 0 $ 0  
Equity method investment, amount of cash calls, based on proportionate ownership interest           400,000  
Equity method investments, increase (decrease) due to foreign currency translation adjustment     $ 6,900,000 $ 3,500,000 (7,800,000) 7,300,000  
Equity investments     $ 13,013,000   $ 13,013,000   21,000,000
Investment in Mammoth Energy Services, Inc.              
Schedule of Equity Method Investments [Line Items]              
Equity method investment, ownership interest, percent     21.50%   21.50%    
Equity investments     $ 0   $ 0   11,005,000
Distributions from equity method investments         $ 0 2,500,000  
Windsor Midstream LLC              
Schedule of Equity Method Investments [Line Items]              
Equity method investment, ownership interest, percent     22.50%   22.50%    
Equity investments     $ 39,000   $ 39,000   39,000
Distributions from equity method investments         $ 0    
Tatex Thailand II, LLC              
Schedule of Equity Method Investments [Line Items]              
Equity method investment, ownership interest, percent     23.50%   23.50%    
Equity investments     $ 0   $ 0   $ 0
Distributions from equity method investments         $ 0 $ 2,100,000  
Athabasca, Peace River And Cold Lake Oil Sands Regions | Investment in Grizzly Oil Sands ULC              
Schedule of Equity Method Investments [Line Items]              
Gas and oil area, reserve (in acres) | a         830    
Phu Horm Field | Apico Llc              
Schedule of Equity Method Investments [Line Items]              
Gas and oil area, reserve (in acres) | a         108    
Apico Llc | Tatex Thailand II, LLC              
Schedule of Equity Method Investments [Line Items]              
Ownership percentage       8.50%   8.50%