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EQUITY INVESMENTS (Narrative) (Details) $ / shares in Units, a in Thousands | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2019 USD ($) a $ / shares shares | Mar. 31, 2018 USD ($) | May 31, 2018 | May 01, 2018
Schedule of Equity Method Investments [Line Items] |  |  |  |
Income from equity method investments, net | $ (4,273,000) | $ (13,536,000) |  |
Distributions from equity method investments | 0 | 750,000 |  |
Mammoth Energy Services LP |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Distributions from equity method investments | $ 1,200,000 |  |  |
Equity method investment, ownership interest (in shares) | shares | 9,831,770 |  |  |
Approximate fair value, quoted market price | $ 163,700,000 |  |  |
Share dividend (in usd per share) | $ / shares | $ 0.125 |  |  |
Tatex Thailand II, LLC |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Income from equity method investments, net | $ (140,000) | (41,000) |  |
Equity method investment, ownership interest, percent | 23.50% |  |  |
Grizzly Oil Sands ULC |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Gas and oil area, reserve (in acres) | a | 830 |  |  |
Equity method investment, impairment | $ 0 | 0 |  |
Income from equity method investments, net | $ 393,000 | 330,000 |  |
Equity method investment, ownership interest, percent | 24.9999% |  |  |
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 | (5,300,000) |  |
Windsor Midstream LLC |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Income from equity method investments, net | $ 0 | 0 |  |
Equity method investment, ownership interest, percent | 22.50% |  |  |
Distributions from equity method investments | $ 0 |  |  |
Mammoth Energy Services LP |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Equity method investments, increase (decrease) due to foreign currency translation adjustment | 100,000 | (200,000) |  |
Strike Force Midstream LLC |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Income from equity method investments, net | $ 0 | (357,000) |  |
Equity method investment, ownership interest, percent | 0.00% |  |  | 25.00%
Distributions from equity method investments |  | $ 800,000 |  |
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% |  |  |
Investee | Mammoth Energy Services LP |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Equity method investment, ownership interest, percent | 21.90% |  |  |
Investee | Strike Force Midstream LLC |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Equity method investment, ownership interest, percent |  |  | 25.00% |

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