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Equity Investments (Investments Accounted for by the Equity Method) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016 | Feb. 29, 2016 | Dec. 31, 2014
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Equity investments and investments in subsidiaries | $ 279,282 |  | $ 279,282 |  | $ 243,920 |  |
(Income) loss from equity method investments | $ 2,737 | $ (5,997) | $ 20,945 | $ 25,576 |  |  |
Investment in Tatex Thailand II, LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 23.50% |  | 23.50% |  |  |  |
Equity investments and investments in subsidiaries | $ 0 |  | $ 0 |  | 0 |  |
(Income) loss from equity method investments | $ (95) | (253) | $ (549) | (412) |  |  |
Investment in Tatex Thailand III, LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 17.90% |  | 17.90% |  |  |  |
Equity investments and investments in subsidiaries | $ 0 |  | $ 0 |  | 0 |  |
(Income) loss from equity method investments | $ 0 | 0 | $ 0 | 0 |  |  |
Investment in Grizzly Oil Sands ULC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 24.9999% |  | 24.9999% |  |  |  |
Equity investments and investments in subsidiaries | $ 58,674 |  | $ 58,674 |  | 45,213 |  |
(Income) loss from equity method investments | $ 296 | 363 | $ 869 | 24,811 |  |  |
Investment in Timber Wolf Terminals LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 50.00% |  | 50.00% |  |  |  |
Equity investments and investments in subsidiaries | $ 983 |  | $ 983 |  | 991 |  |
(Income) loss from equity method investments | $ 4 | 3 | $ 8 | 7 |  |  |
Investment in Windsor Midstream LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 22.50% |  | 22.50% |  |  |  |
Equity investments and investments in subsidiaries | $ 31 |  | $ 31 |  | 25,749 |  |
(Income) loss from equity method investments | $ (2) | (9,014) | $ 25,232 | (12,062) |  |  |
Investment in Stingray Cementing LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 0.00% |  | 0.00% |  |  |  |
Equity investments and investments in subsidiaries | $ 0 |  | $ 0 |  | 1,920 |  |
(Income) loss from equity method investments | $ 0 | 79 | $ 205 | 187 |  |  |
Investment in Blackhawk Midstream LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 48.50% |  | 48.50% |  |  |  |
Equity investments and investments in subsidiaries | $ 0 |  | $ 0 |  | 0 |  |
(Income) loss from equity method investments | $ 0 | 0 | $ 0 | 0 |  |  |
Investment in Stingray Energy Services LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 0.00% |  | 0.00% |  |  |  |
Equity investments and investments in subsidiaries | $ 0 |  | $ 0 |  | 4,215 |  |
(Income) loss from equity method investments | $ 0 | 294 | $ 282 | 935 |  |  |
Investment in Sturgeon Acquisitions LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 0.00% |  | 0.00% |  |  |  | 25.00%
Equity investments and investments in subsidiaries | $ 0 |  | $ 0 |  | 20,526 |  |
(Income) loss from equity method investments | $ 0 | 112 | $ (71) | 623 |  |  |
Investment in Mammoth Energy Services, Inc. |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 25.10% |  | 25.10% |  |  |  |
Equity investments and investments in subsidiaries | $ 149,219 |  | $ 149,219 |  | 111,717 |  |
(Income) loss from equity method investments | $ 2,407 | 2,518 | $ (7,616) | 11,527 |  |  |
Investment in Strike Force Midstream LLC |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Approximate ownership % | 25.00% |  | 25.00% |  |  | 25.00% |
Equity investments and investments in subsidiaries | $ 70,375 |  | $ 70,375 |  | $ 33,589 |  |
(Income) loss from equity method investments | $ 127 | $ (99) | $ 2,585 | $ (40) |  |  |

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