Property, Plant And Equipment (Schedule of Property Plant and Equipment) (Details) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Property, Plant and Equipment [Line Items] | ||
| Proved properties | $ 1,286,373 | $ 1,124,367 |
| Total oil and natural gas properties | 1,378,982 | 1,252,641 |
| Total property and equipment | 1,382,050 | 1,255,651 |
| Impairment of proved natural gas and oil properties | (764,817) | (337,939) |
| Accumulated depreciation, depletion and amortization | (288,299) | (225,412) |
| Total accumulated depreciation, depletion and amortization | (1,053,116) | (563,351) |
| Total property, plant and equipment, net | 328,934 | 692,300 |
| Total oil and natural gas properties | ||
| Property, Plant and Equipment [Line Items] | ||
| Unproved properties | 92,609 | 128,274 |
| Proved properties | 1,286,373 | 1,124,367 |
| Total oil and natural gas properties | 1,378,982 | 1,252,641 |
| Furniture and equipment | ||
| Property, Plant and Equipment [Line Items] | ||
| Total property and equipment | $ 3,068 | $ 3,010 |