Condensed Consolidating Financial Information - Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Thousands |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Current assets: |
|
|
|
|
Cash and cash equivalents |
$ 99,557
|
$ 1,275,875
|
$ 112,974
|
$ 142,340
|
Restricted cash |
0
|
185,000
|
|
|
Accounts receivable—oil and natural gas |
182,213
|
136,761
|
|
|
Accounts receivable - related parties |
0
|
16
|
|
|
Accounts receivable - intercompany |
0
|
0
|
|
|
Prepaid expenses and other current assets |
4,912
|
3,135
|
|
|
Short-term derivative instruments - asset |
78,847
|
3,488
|
|
|
Total current assets |
365,529
|
1,604,275
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties, full-cost accounting |
9,169,156
|
6,071,920
|
|
|
Other property and equipment |
86,754
|
68,986
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(4,153,733)
|
(3,789,780)
|
|
|
Property and equipment, net |
5,102,177
|
2,351,126
|
|
|
Other assets: |
|
|
|
|
Equity investments and investments in subsidiaries |
302,112
|
243,920
|
|
|
Long-term derivative instruments |
8,685
|
5,696
|
|
|
Deferred tax asset |
1,208
|
4,692
|
|
|
Inventories |
8,227
|
4,504
|
|
|
Other assets |
19,814
|
8,932
|
|
|
Total other assets |
340,046
|
267,744
|
|
|
Total assets |
5,807,752
|
4,223,145
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
553,609
|
265,124
|
|
|
Accounts payable - intercompany |
0
|
0
|
|
|
Asset retirement obligation—current |
120
|
195
|
|
|
Short-term derivative instruments |
32,534
|
119,219
|
|
|
Current maturities of long-term debt |
622
|
276
|
|
|
Total current liabilities |
586,885
|
384,814
|
|
|
Long-term derivative instruments |
2,989
|
26,759
|
|
|
Asset retirement obligation—long-term |
74,980
|
34,081
|
|
|
Other non-current liabilities |
2,963
|
0
|
|
|
Long-term debt, net of current maturities |
2,038,321
|
1,593,599
|
|
|
Total liabilities |
2,706,138
|
2,039,253
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
1,831
|
1,588
|
|
|
Paid-in capital |
4,416,250
|
3,946,442
|
|
|
Accumulated other comprehensive (loss) income |
(40,539)
|
(53,058)
|
|
|
Retained (deficit) earnings |
(1,275,928)
|
(1,711,080)
|
|
|
Total stockholders’ equity |
3,101,614
|
2,183,892
|
2,038,837
|
2,296,296
|
Total liabilities and stockholders’ equity |
5,807,752
|
4,223,145
|
|
|
Parent |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
67,908
|
1,273,882
|
112,494
|
141,535
|
Restricted cash |
|
185,000
|
|
|
Accounts receivable—oil and natural gas |
128,121
|
137,087
|
|
|
Accounts receivable - related parties |
0
|
16
|
|
|
Accounts receivable - intercompany |
554,439
|
449,517
|
|
|
Prepaid expenses and other current assets |
4,719
|
3,135
|
|
|
Short-term derivative instruments - asset |
78,847
|
3,488
|
|
|
Total current assets |
834,034
|
2,052,125
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties, full-cost accounting |
6,562,147
|
5,655,125
|
|
|
Other property and equipment |
86,711
|
68,943
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(4,153,696)
|
(3,789,746)
|
|
|
Property and equipment, net |
2,495,162
|
1,934,322
|
|
|
Other assets: |
|
|
|
|
Equity investments and investments in subsidiaries |
2,361,575
|
236,327
|
|
|
Long-term derivative instruments |
8,685
|
5,696
|
|
|
Deferred tax asset |
1,208
|
4,692
|
|
|
Inventories |
5,816
|
3,095
|
|
|
Other assets |
12,483
|
8,932
|
|
|
Total other assets |
2,389,767
|
258,742
|
|
|
Total assets |
5,718,963
|
4,245,189
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
416,249
|
255,966
|
|
|
Accounts payable - intercompany |
63,373
|
31,202
|
|
|
Asset retirement obligation—current |
120
|
195
|
|
|
Short-term derivative instruments |
32,534
|
119,219
|
|
|
Current maturities of long-term debt |
622
|
276
|
|
|
Total current liabilities |
512,898
|
406,858
|
|
|
Long-term derivative instruments |
2,989
|
26,759
|
|
|
Asset retirement obligation—long-term |
63,141
|
34,081
|
|
|
Other non-current liabilities |
0
|
|
|
|
Long-term debt, net of current maturities |
2,038,321
|
1,593,599
|
|
|
Total liabilities |
2,617,349
|
2,061,297
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
1,831
|
1,588
|
|
|
Paid-in capital |
4,416,250
|
3,946,442
|
|
|
Accumulated other comprehensive (loss) income |
(40,539)
|
(53,058)
|
|
|
Retained (deficit) earnings |
(1,275,928)
|
(1,711,080)
|
|
|
Total stockholders’ equity |
3,101,614
|
2,183,892
|
|
|
Total liabilities and stockholders’ equity |
5,718,963
|
4,245,189
|
|
|
Guarantors |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
31,649
|
1,993
|
479
|
804
|
Restricted cash |
|
0
|
|
|
Accounts receivable—oil and natural gas |
54,092
|
37,496
|
|
|
Accounts receivable - related parties |
0
|
0
|
|
|
Accounts receivable - intercompany |
63,374
|
1,151
|
|
|
Prepaid expenses and other current assets |
193
|
0
|
|
|
Short-term derivative instruments - asset |
0
|
0
|
|
|
Total current assets |
149,308
|
40,640
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties, full-cost accounting |
2,607,738
|
417,524
|
|
|
Other property and equipment |
43
|
43
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(37)
|
(34)
|
|
|
Property and equipment, net |
2,607,744
|
417,533
|
|
|
Other assets: |
|
|
|
|
Equity investments and investments in subsidiaries |
77,744
|
33,590
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Deferred tax asset |
0
|
0
|
|
|
Inventories |
2,411
|
1,409
|
|
|
Other assets |
7,331
|
0
|
|
|
Total other assets |
87,486
|
34,999
|
|
|
Total assets |
2,844,538
|
493,172
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
137,361
|
9,158
|
|
|
Accounts payable - intercompany |
554,313
|
457,163
|
|
|
Asset retirement obligation—current |
0
|
0
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Current maturities of long-term debt |
0
|
0
|
|
|
Total current liabilities |
691,674
|
466,321
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Asset retirement obligation—long-term |
11,839
|
0
|
|
|
Other non-current liabilities |
2,963
|
|
|
|
Long-term debt, net of current maturities |
0
|
0
|
|
|
Total liabilities |
706,476
|
466,321
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
0
|
0
|
|
|
Paid-in capital |
1,915,598
|
33,822
|
|
|
Accumulated other comprehensive (loss) income |
0
|
0
|
|
|
Retained (deficit) earnings |
222,464
|
(6,971)
|
|
|
Total stockholders’ equity |
2,138,062
|
26,851
|
|
|
Total liabilities and stockholders’ equity |
2,844,538
|
493,172
|
|
|
Non-Guarantor |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
0
|
0
|
1
|
1
|
Restricted cash |
0
|
0
|
|
|
Accounts receivable—oil and natural 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 - asset |
0
|
0
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties, full-cost accounting |
0
|
0
|
|
|
Other property and equipment |
0
|
0
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
0
|
0
|
|
|
Property and equipment, net |
0
|
0
|
|
|
Other assets: |
|
|
|
|
Equity investments and investments in subsidiaries |
57,641
|
45,213
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Deferred tax asset |
0
|
0
|
|
|
Inventories |
0
|
0
|
|
|
Other assets |
0
|
0
|
|
|
Total other assets |
57,641
|
45,213
|
|
|
Total assets |
57,641
|
45,213
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
0
|
0
|
|
|
Accounts payable - intercompany |
127
|
126
|
|
|
Asset retirement obligation—current |
0
|
0
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Current maturities of long-term debt |
0
|
0
|
|
|
Total current liabilities |
127
|
126
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Asset retirement obligation—long-term |
0
|
0
|
|
|
Other non-current liabilities |
0
|
|
|
|
Long-term debt, net of current maturities |
0
|
0
|
|
|
Total liabilities |
127
|
126
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
0
|
0
|
|
|
Paid-in capital |
259,307
|
257,026
|
|
|
Accumulated other comprehensive (loss) income |
(38,593)
|
(50,931)
|
|
|
Retained (deficit) earnings |
(163,200)
|
(161,008)
|
|
|
Total stockholders’ equity |
57,514
|
45,087
|
|
|
Total liabilities and stockholders’ equity |
57,641
|
45,213
|
|
|
Eliminations |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
0
|
0
|
$ 0
|
$ 0
|
Restricted cash |
0
|
0
|
|
|
Accounts receivable—oil and natural gas |
|
(37,822)
|
|
|
Accounts receivable - related parties |
0
|
0
|
|
|
Accounts receivable - intercompany |
(617,813)
|
(450,668)
|
|
|
Prepaid expenses and other current assets |
0
|
0
|
|
|
Short-term derivative instruments - asset |
0
|
0
|
|
|
Total current assets |
(617,813)
|
(488,490)
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties, full-cost accounting |
(729)
|
(729)
|
|
|
Other property and equipment |
0
|
0
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
0
|
0
|
|
|
Property and equipment, net |
(729)
|
(729)
|
|
|
Other assets: |
|
|
|
|
Equity investments and investments in subsidiaries |
(2,194,848)
|
(71,210)
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Deferred tax asset |
0
|
0
|
|
|
Inventories |
0
|
0
|
|
|
Other assets |
0
|
0
|
|
|
Total other assets |
(2,194,848)
|
(71,210)
|
|
|
Total assets |
(2,813,390)
|
(560,429)
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
(1)
|
0
|
|
|
Accounts payable - intercompany |
(617,813)
|
(488,491)
|
|
|
Asset retirement obligation—current |
0
|
0
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Current maturities of long-term debt |
0
|
0
|
|
|
Total current liabilities |
(617,814)
|
(488,491)
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Asset retirement obligation—long-term |
0
|
0
|
|
|
Other non-current liabilities |
0
|
|
|
|
Long-term debt, net of current maturities |
0
|
0
|
|
|
Total liabilities |
(617,814)
|
(488,491)
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
0
|
0
|
|
|
Paid-in capital |
(2,174,905)
|
(290,848)
|
|
|
Accumulated other comprehensive (loss) income |
38,593
|
50,931
|
|
|
Retained (deficit) earnings |
(59,264)
|
167,979
|
|
|
Total stockholders’ equity |
(2,195,576)
|
(71,938)
|
|
|
Total liabilities and stockholders’ equity |
$ (2,813,390)
|
$ (560,429)
|
|
|