Condensed Consolidating Financial Information - Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Thousands |
Jun. 30, 2016 |
Dec. 31, 2015 |
Jun. 30, 2015 |
Dec. 31, 2014 |
Current assets: |
|
|
|
|
Cash and cash equivalents |
$ 396,437
|
$ 112,974
|
$ 525,488
|
$ 142,340
|
Accounts receivable—oil and gas |
91,462
|
71,872
|
|
|
Accounts receivable - related parties |
23
|
16
|
|
|
Accounts receivable - intercompany |
|
0
|
|
|
Prepaid expenses and other current assets |
7,782
|
3,905
|
|
|
Short-term derivative instruments |
44,672
|
142,794
|
|
|
Deferred Tax Assets, Net, Current |
292
|
0
|
|
|
Total current assets |
540,668
|
331,561
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
5,686,188
|
5,424,342
|
|
|
Other property and equipment |
48,107
|
33,171
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(3,339,087)
|
(2,829,110)
|
|
|
Property and equipment, net |
2,395,208
|
2,628,403
|
|
|
Other assets: |
|
|
|
|
Equity investments |
253,047
|
242,393
|
|
|
Long-term derivative instruments |
14,644
|
51,088
|
|
|
Deferred tax asset |
24,284
|
74,925
|
|
|
Other assets |
11,336
|
6,364
|
|
|
Total other assets |
303,311
|
374,770
|
|
|
Total assets |
3,239,187
|
3,334,734
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
289,750
|
265,128
|
|
|
Accounts payable - intercompany |
0
|
0
|
|
|
Asset retirement obligation—current |
75
|
75
|
75
|
|
Short-term derivative instruments |
49,906
|
437
|
|
|
Deferred tax liability |
0
|
50,697
|
|
|
Current maturities of long-term debt |
0
|
179
|
|
|
Total current liabilities |
339,731
|
316,516
|
|
|
Long-term derivative instrument |
29,269
|
6,935
|
|
|
Asset retirement obligation—long-term |
29,993
|
26,362
|
21,202
|
|
Asset retirement obligation - long-term |
|
26,362
|
|
|
Long-term debt |
956,754
|
946,084
|
|
|
Total liabilities |
1,355,747
|
1,295,897
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
1,253
|
1,082
|
|
|
Paid-in capital |
3,242,404
|
2,824,303
|
|
|
Accumulated other comprehensive (loss) income |
(46,803)
|
(55,177)
|
|
|
Retained (deficit) earnings |
(1,313,414)
|
(731,371)
|
|
|
Total stockholders’ equity |
1,883,440
|
2,038,837
|
3,267,306
|
2,296,296
|
Total liabilities and stockholders’ equity |
3,239,187
|
3,334,734
|
|
|
Parent |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
395,703
|
112,494
|
524,240
|
141,535
|
Accounts receivable—oil and gas |
90,758
|
72,241
|
|
|
Accounts receivable - related parties |
23
|
16
|
|
|
Accounts receivable - intercompany |
355,924
|
326,475
|
|
|
Prepaid expenses and other current assets |
7,782
|
3,905
|
|
|
Short-term derivative instruments |
44,672
|
142,794
|
|
|
Deferred Tax Assets, Net, Current |
292
|
|
|
|
Total current assets |
895,154
|
657,925
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
5,334,096
|
5,108,258
|
|
|
Other property and equipment |
48,064
|
33,128
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(3,339,056)
|
(2,829,081)
|
|
|
Property and equipment, net |
2,043,104
|
2,312,305
|
|
|
Other assets: |
|
|
|
|
Equity investments |
242,627
|
231,892
|
|
|
Long-term derivative instruments |
14,644
|
51,088
|
|
|
Deferred tax asset |
24,284
|
74,925
|
|
|
Other assets |
11,336
|
6,364
|
|
|
Total other assets |
292,891
|
364,269
|
|
|
Total assets |
3,231,149
|
3,334,499
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
281,712
|
264,893
|
|
|
Accounts payable - intercompany |
0
|
|
|
|
Asset retirement obligation—current |
75
|
75
|
|
|
Short-term derivative instruments |
49,906
|
437
|
|
|
Deferred tax liability |
|
50,697
|
|
|
Current maturities of long-term debt |
|
179
|
|
|
Total current liabilities |
331,693
|
316,281
|
|
|
Long-term derivative instrument |
29,269
|
6,935
|
|
|
Asset retirement obligation—long-term |
29,993
|
|
|
|
Asset retirement obligation - long-term |
|
26,362
|
|
|
Long-term debt |
956,754
|
946,084
|
|
|
Total liabilities |
1,347,709
|
1,295,662
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
1,253
|
1,082
|
|
|
Paid-in capital |
3,242,404
|
2,824,303
|
|
|
Accumulated other comprehensive (loss) income |
(46,803)
|
(55,177)
|
|
|
Retained (deficit) earnings |
(1,313,414)
|
(731,371)
|
|
|
Total stockholders’ equity |
1,883,440
|
2,038,837
|
|
|
Total liabilities and stockholders’ equity |
3,231,149
|
3,334,499
|
|
|
Guarantors |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
733
|
479
|
1,247
|
804
|
Accounts receivable—oil and gas |
7,721
|
54
|
|
|
Accounts receivable - related parties |
0
|
0
|
|
|
Accounts receivable - intercompany |
1,904
|
60
|
|
|
Prepaid expenses and other current assets |
|
0
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Deferred Tax Assets, Net, Current |
0
|
|
|
|
Total current assets |
10,358
|
593
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
352,821
|
316,813
|
|
|
Other property and equipment |
43
|
43
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(31)
|
(29)
|
|
|
Property and equipment, net |
352,833
|
316,827
|
|
|
Other assets: |
|
|
|
|
Equity investments |
25,441
|
0
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Deferred tax asset |
0
|
0
|
|
|
Other assets |
|
0
|
|
|
Total other assets |
25,441
|
|
|
|
Total assets |
388,632
|
317,420
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
16,768
|
527
|
|
|
Accounts payable - intercompany |
355,991
|
326,541
|
|
|
Asset retirement obligation—current |
|
0
|
|
|
Short-term derivative instruments |
|
0
|
|
|
Deferred tax liability |
|
0
|
|
|
Current maturities of long-term debt |
|
0
|
|
|
Total current liabilities |
372,759
|
327,068
|
|
|
Long-term derivative instrument |
0
|
0
|
|
|
Asset retirement obligation—long-term |
0
|
|
|
|
Asset retirement obligation - long-term |
|
0
|
|
|
Long-term debt |
0
|
0
|
|
|
Total liabilities |
372,759
|
327,068
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
|
0
|
|
|
Paid-in capital |
25,822
|
322
|
|
|
Accumulated other comprehensive (loss) income |
|
0
|
|
|
Retained (deficit) earnings |
(9,949)
|
(9,970)
|
|
|
Total stockholders’ equity |
15,873
|
(9,648)
|
|
|
Total liabilities and stockholders’ equity |
388,632
|
317,420
|
|
|
Non-Guarantor |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
1
|
1
|
1
|
1
|
Accounts receivable—oil and gas |
0
|
0
|
|
|
Accounts receivable - related parties |
0
|
0
|
|
|
Accounts receivable - intercompany |
0
|
0
|
|
|
Prepaid expenses and other current assets |
0
|
0
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Deferred Tax Assets, Net, Current |
0
|
|
|
|
Total current assets |
1
|
1
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
|
0
|
|
|
Other property and equipment |
|
0
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
|
0
|
|
|
Property and equipment, net |
|
0
|
|
|
Other assets: |
|
|
|
|
Equity investments |
49,557
|
50,644
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Deferred tax asset |
0
|
0
|
|
|
Other assets |
|
0
|
|
|
Total other assets |
49,557
|
50,644
|
|
|
Total assets |
49,558
|
50,645
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
|
0
|
|
|
Accounts payable - intercompany |
125
|
124
|
|
|
Asset retirement obligation—current |
|
0
|
|
|
Short-term derivative instruments |
|
0
|
|
|
Deferred tax liability |
|
0
|
|
|
Current maturities of long-term debt |
|
0
|
|
|
Total current liabilities |
125
|
124
|
|
|
Long-term derivative instrument |
0
|
0
|
|
|
Asset retirement obligation—long-term |
0
|
|
|
|
Asset retirement obligation - long-term |
|
0
|
|
|
Long-term debt |
0
|
0
|
|
|
Total liabilities |
125
|
124
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
|
0
|
|
|
Paid-in capital |
255,244
|
241,553
|
|
|
Accumulated other comprehensive (loss) income |
(45,507)
|
(55,177)
|
|
|
Retained (deficit) earnings |
(160,304)
|
(135,855)
|
|
|
Total stockholders’ equity |
49,433
|
50,521
|
|
|
Total liabilities and stockholders’ equity |
49,558
|
50,645
|
|
|
Eliminations |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
0
|
0
|
$ 0
|
$ 0
|
Accounts receivable—oil and gas |
(7,017)
|
(423)
|
|
|
Accounts receivable - related parties |
0
|
0
|
|
|
Accounts receivable - intercompany |
(357,828)
|
(326,535)
|
|
|
Prepaid expenses and other current assets |
|
0
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Deferred Tax Assets, Net, Current |
0
|
|
|
|
Total current assets |
(364,845)
|
(326,958)
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
(729)
|
(729)
|
|
|
Other property and equipment |
|
0
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
|
0
|
|
|
Property and equipment, net |
(729)
|
(729)
|
|
|
Other assets: |
|
|
|
|
Equity investments |
(64,578)
|
(40,143)
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Deferred tax asset |
0
|
0
|
|
|
Other assets |
|
0
|
|
|
Total other assets |
(64,578)
|
(40,143)
|
|
|
Total assets |
(430,152)
|
(367,830)
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
(8,730)
|
(292)
|
|
|
Accounts payable - intercompany |
(356,116)
|
(326,665)
|
|
|
Asset retirement obligation—current |
|
0
|
|
|
Short-term derivative instruments |
|
0
|
|
|
Deferred tax liability |
|
0
|
|
|
Current maturities of long-term debt |
|
0
|
|
|
Total current liabilities |
(364,846)
|
(326,957)
|
|
|
Long-term derivative instrument |
0
|
0
|
|
|
Asset retirement obligation—long-term |
0
|
|
|
|
Asset retirement obligation - long-term |
|
0
|
|
|
Long-term debt |
0
|
0
|
|
|
Total liabilities |
(364,846)
|
(326,957)
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
|
0
|
|
|
Paid-in capital |
(281,066)
|
(241,875)
|
|
|
Accumulated other comprehensive (loss) income |
45,507
|
55,177
|
|
|
Retained (deficit) earnings |
170,253
|
145,825
|
|
|
Total stockholders’ equity |
(65,306)
|
(40,873)
|
|
|
Total liabilities and stockholders’ equity |
$ (430,152)
|
$ (367,830)
|
|
|