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 9 Months Ended
May 31, 2019
$ / shares
Feb. 28, 2019
$ / shares
Sep. 30, 2020
USD ($)
shares
Sep. 30, 2019
USD ($)
Sep. 30, 2020
USD ($)
a
shares
Sep. 30, 2019
USD ($)
Mar. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Schedule of Equity Method Investments [Line Items]                
Equity investments     $ 16,560,000   $ 16,560,000     $ 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     $ 15,700,000   $ 15,700,000      
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     $ (3,700,000) $ 2,000,000.0 4,100,000 (5,200,000)    
Equity investments     $ 16,521,000   $ 16,521,000     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   $ 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%