Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($)
$ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Oil and natural gas properties |
|
|
| Proved |
$ 12,093,492
|
$ 12,529,681
|
| Unproved |
322,580
|
363,149
|
| Total oil and natural gas properties |
12,416,072
|
12,892,830
|
| Less: accumulated depreciation, depletion and impairment |
(11,637,538)
|
(11,149,888)
|
| Net oil and natural gas properties capitalized costs |
778,534
|
1,742,942
|
| Land |
5,210
|
14,260
|
| Non-oil and natural gas equipment |
240,402
|
373,687
|
| Buildings and structures |
228,753
|
227,673
|
| Total |
474,365
|
615,620
|
| Less accumulated depreciation and amortization |
(116,837)
|
(123,860)
|
| Other property, plant and equipment, net |
357,528
|
491,760
|
| Total property, plant and equipment, net |
1,136,062
|
2,234,702
|
| Oil and natural gas proved properties |
|
|
| Property, Plant and Equipment |
|
|
| Cumulative capitalized interest |
51,100
|
48,900
|
| Non-oil and natural gas equipment |
|
|
| Property, Plant and Equipment |
|
|
| Cumulative capitalized interest |
4,300
|
4,300
|
| Buildings and structures |
|
|
| Property, Plant and Equipment |
|
|
| Cumulative capitalized interest |
$ 20,400
|
$ 20,400
|