CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Balance Sheets) (Details) - USD ($) $ in Thousands |
Mar. 31, 2020 |
Dec. 31, 2019 |
Mar. 31, 2019 |
Dec. 31, 2018 |
Current assets: |
|
|
|
|
Cash and cash equivalents |
$ 1,633
|
$ 6,060
|
|
|
Accounts receivable - oil and natural gas sales |
74,099
|
121,210
|
|
|
Accounts receivable - joint interest and other |
42,547
|
47,975
|
|
|
Accounts receivable - intercompany |
0
|
0
|
|
|
Prepaid expenses and other current assets |
11,848
|
4,431
|
|
|
Short-term derivative instruments |
171,755
|
126,201
|
|
|
Total current assets |
301,882
|
305,877
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
10,667,532
|
10,595,735
|
|
|
Other property and equipment |
96,882
|
96,719
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(7,859,873)
|
(7,228,660)
|
|
|
Property and equipment, net |
2,904,541
|
3,463,794
|
|
|
Other assets: |
|
|
|
|
Equity investments and investments in subsidiaries |
6,225
|
32,044
|
|
|
Long-term derivative instruments |
0
|
563
|
|
|
Deferred tax asset |
0
|
7,563
|
|
|
Operating lease assets |
10,186
|
14,168
|
|
|
Operating lease assets—related parties |
0
|
43,270
|
|
|
Other assets |
41,453
|
15,540
|
|
|
Total other assets |
57,864
|
113,148
|
|
|
Total assets |
3,264,287
|
3,882,819
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
437,453
|
415,218
|
|
|
Accounts payable - intercompany |
0
|
0
|
|
|
Short-term derivative instruments |
67
|
303
|
|
|
Current portion of operating lease liabilities |
9,873
|
13,826
|
|
|
Current portion of operating lease liabilities—related parties |
0
|
21,220
|
|
|
Current maturities of long-term debt |
688
|
631
|
|
|
Total current liabilities |
448,081
|
451,198
|
|
|
Long-term derivative instruments |
70,829
|
53,135
|
|
|
Asset retirement obligation |
59,444
|
60,355
|
|
|
Uncertain tax position liability |
3,209
|
3,127
|
|
|
Non-current operating lease liabilities |
313
|
342
|
|
|
Non-current operating lease liabilities—related parties |
0
|
22,050
|
|
|
Long-term debt, net of current maturities |
1,898,362
|
1,978,020
|
|
|
Total liabilities |
2,480,238
|
2,568,227
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
1,598
|
1,597
|
|
|
Paid-in capital |
4,209,578
|
4,207,554
|
|
|
Accumulated other comprehensive loss |
(61,863)
|
(46,833)
|
|
|
Accumulated deficit |
(3,365,264)
|
(2,847,726)
|
|
|
Total stockholders’ equity |
784,049
|
1,314,592
|
$ 3,368,266
|
$ 3,327,768
|
Total liabilities and stockholders’ equity |
3,264,287
|
3,882,819
|
|
|
Reportable legal entities | Parent |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
897
|
2,768
|
|
|
Accounts receivable - oil and natural gas sales |
860
|
859
|
|
|
Accounts receivable - joint interest and other |
8,521
|
5,279
|
|
|
Accounts receivable - intercompany |
1,277,124
|
1,065,593
|
|
|
Prepaid expenses and other current assets |
11,452
|
4,047
|
|
|
Short-term derivative instruments |
171,755
|
126,201
|
|
|
Total current assets |
1,470,609
|
1,204,747
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
1,247,661
|
1,314,933
|
|
|
Other property and equipment |
92,812
|
92,650
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(1,421,230)
|
(1,418,888)
|
|
|
Property and equipment, net |
(80,757)
|
(11,305)
|
|
|
Other assets: |
|
|
|
|
Equity investments and investments in subsidiaries |
2,486,108
|
3,064,503
|
|
|
Long-term derivative instruments |
|
563
|
|
|
Deferred tax asset |
|
7,563
|
|
|
Operating lease assets |
10,186
|
14,168
|
|
|
Operating lease assets—related parties |
|
43,270
|
|
|
Other assets |
32,591
|
10,026
|
|
|
Total other assets |
2,528,885
|
3,140,093
|
|
|
Total assets |
3,918,737
|
4,333,535
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
63,863
|
48,006
|
|
|
Accounts payable - intercompany |
1,087,484
|
878,283
|
|
|
Short-term derivative instruments |
67
|
303
|
|
|
Current portion of operating lease liabilities |
9,873
|
13,826
|
|
|
Current portion of operating lease liabilities—related parties |
|
21,220
|
|
|
Current maturities of long-term debt |
688
|
631
|
|
|
Total current liabilities |
1,161,975
|
962,269
|
|
|
Long-term derivative instruments |
70,829
|
53,135
|
|
|
Asset retirement obligation |
0
|
0
|
|
|
Uncertain tax position liability |
3,209
|
3,127
|
|
|
Non-current operating lease liabilities |
313
|
342
|
|
|
Non-current operating lease liabilities—related parties |
|
22,050
|
|
|
Long-term debt, net of current maturities |
1,898,362
|
1,978,020
|
|
|
Total liabilities |
3,134,688
|
3,018,943
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
1,598
|
1,597
|
|
|
Paid-in capital |
4,209,578
|
4,207,554
|
|
|
Accumulated other comprehensive loss |
(61,863)
|
(46,833)
|
|
|
Accumulated deficit |
(3,365,264)
|
(2,847,726)
|
|
|
Total stockholders’ equity |
784,049
|
1,314,592
|
|
|
Total liabilities and stockholders’ equity |
3,918,737
|
4,333,535
|
|
|
Reportable legal entities | Guarantors |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
541
|
3,097
|
|
|
Accounts receivable - oil and natural gas sales |
73,239
|
120,351
|
|
|
Accounts receivable - joint interest and other |
34,026
|
42,696
|
|
|
Accounts receivable - intercompany |
1,052,317
|
843,223
|
|
|
Prepaid expenses and other current assets |
320
|
308
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Total current assets |
1,160,443
|
1,009,675
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
9,414,738
|
9,273,681
|
|
|
Other property and equipment |
51
|
50
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(6,436,959)
|
(5,808,254)
|
|
|
Property and equipment, net |
2,977,830
|
3,465,477
|
|
|
Other assets: |
|
|
|
|
Equity investments and investments in subsidiaries |
6,332
|
6,332
|
|
|
Long-term derivative instruments |
|
0
|
|
|
Deferred tax asset |
|
0
|
|
|
Operating lease assets |
0
|
0
|
|
|
Operating lease assets—related parties |
|
0
|
|
|
Other assets |
8,863
|
5,514
|
|
|
Total other assets |
15,195
|
11,846
|
|
|
Total assets |
4,153,468
|
4,486,998
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
373,554
|
367,088
|
|
|
Accounts payable - intercompany |
1,237,368
|
1,026,249
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Current portion of operating lease liabilities |
0
|
0
|
|
|
Current portion of operating lease liabilities—related parties |
|
0
|
|
|
Current maturities of long-term debt |
0
|
0
|
|
|
Total current liabilities |
1,610,922
|
1,393,337
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Asset retirement obligation |
59,444
|
58,322
|
|
|
Uncertain tax position liability |
0
|
0
|
|
|
Non-current operating lease liabilities |
0
|
0
|
|
|
Non-current operating lease liabilities—related parties |
|
0
|
|
|
Long-term debt, net of current maturities |
0
|
0
|
|
|
Total liabilities |
1,670,366
|
1,451,659
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
0
|
0
|
|
|
Paid-in capital |
4,171,409
|
4,171,408
|
|
|
Accumulated other comprehensive loss |
0
|
0
|
|
|
Accumulated deficit |
(1,688,307)
|
(1,136,069)
|
|
|
Total stockholders’ equity |
2,483,102
|
3,035,339
|
|
|
Total liabilities and stockholders’ equity |
4,153,468
|
4,486,998
|
|
|
Reportable legal entities | Non-Guarantors |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
195
|
195
|
|
|
Accounts receivable - oil and natural gas sales |
0
|
0
|
|
|
Accounts receivable - joint interest and other |
0
|
0
|
|
|
Accounts receivable - intercompany |
0
|
0
|
|
|
Prepaid expenses and other current assets |
76
|
76
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Total current assets |
271
|
271
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
5,862
|
7,850
|
|
|
Other property and equipment |
4,019
|
4,019
|
|
|
Accumulated depletion, depreciation, amortization and impairment |
(1,684)
|
(1,518)
|
|
|
Property and equipment, net |
8,197
|
10,351
|
|
|
Other assets: |
|
|
|
|
Equity investments and investments in subsidiaries |
6,186
|
21,000
|
|
|
Long-term derivative instruments |
|
0
|
|
|
Deferred tax asset |
|
0
|
|
|
Operating lease assets |
0
|
0
|
|
|
Operating lease assets—related parties |
|
0
|
|
|
Other assets |
(1)
|
0
|
|
|
Total other assets |
6,185
|
21,000
|
|
|
Total assets |
14,653
|
31,622
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
36
|
124
|
|
|
Accounts payable - intercompany |
4,589
|
4,285
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Current portion of operating lease liabilities |
0
|
0
|
|
|
Current portion of operating lease liabilities—related parties |
|
0
|
|
|
Current maturities of long-term debt |
0
|
0
|
|
|
Total current liabilities |
4,625
|
4,409
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Asset retirement obligation |
0
|
2,033
|
|
|
Uncertain tax position liability |
0
|
0
|
|
|
Non-current operating lease liabilities |
0
|
0
|
|
|
Non-current operating lease liabilities—related parties |
|
0
|
|
|
Long-term debt, net of current maturities |
0
|
0
|
|
|
Total liabilities |
4,625
|
6,442
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
0
|
0
|
|
|
Paid-in capital |
267,558
|
267,557
|
|
|
Accumulated other comprehensive loss |
(59,434)
|
(44,763)
|
|
|
Accumulated deficit |
(198,096)
|
(197,614)
|
|
|
Total stockholders’ equity |
10,028
|
25,180
|
|
|
Total liabilities and stockholders’ equity |
14,653
|
31,622
|
|
|
Eliminations |
|
|
|
|
Current assets: |
|
|
|
|
Cash and cash equivalents |
0
|
0
|
|
|
Accounts receivable - oil and natural gas sales |
0
|
0
|
|
|
Accounts receivable - joint interest and other |
0
|
0
|
|
|
Accounts receivable - intercompany |
(2,329,441)
|
(1,908,816)
|
|
|
Prepaid expenses and other current assets |
0
|
0
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Total current assets |
(2,329,441)
|
(1,908,816)
|
|
|
Property and equipment: |
|
|
|
|
Oil and natural gas properties |
(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 |
(2,492,401)
|
(3,059,791)
|
|
|
Long-term derivative instruments |
|
0
|
|
|
Deferred tax asset |
|
0
|
|
|
Operating lease assets |
0
|
0
|
|
|
Operating lease assets—related parties |
|
0
|
|
|
Other assets |
0
|
0
|
|
|
Total other assets |
(2,492,401)
|
(3,059,791)
|
|
|
Total assets |
(4,822,571)
|
(4,969,336)
|
|
|
Current liabilities: |
|
|
|
|
Accounts payable and accrued liabilities |
0
|
0
|
|
|
Accounts payable - intercompany |
(2,329,441)
|
(1,908,817)
|
|
|
Short-term derivative instruments |
0
|
0
|
|
|
Current portion of operating lease liabilities |
0
|
0
|
|
|
Current portion of operating lease liabilities—related parties |
|
0
|
|
|
Current maturities of long-term debt |
0
|
0
|
|
|
Total current liabilities |
(2,329,441)
|
(1,908,817)
|
|
|
Long-term derivative instruments |
0
|
0
|
|
|
Asset retirement obligation |
0
|
0
|
|
|
Uncertain tax position liability |
0
|
0
|
|
|
Non-current operating lease liabilities |
0
|
0
|
|
|
Non-current operating lease liabilities—related parties |
|
0
|
|
|
Long-term debt, net of current maturities |
0
|
0
|
|
|
Total liabilities |
(2,329,441)
|
(1,908,817)
|
|
|
Stockholders’ equity: |
|
|
|
|
Common stock |
0
|
0
|
|
|
Paid-in capital |
(4,438,967)
|
(4,438,965)
|
|
|
Accumulated other comprehensive loss |
59,434
|
44,763
|
|
|
Accumulated deficit |
1,886,403
|
1,333,683
|
|
|
Total stockholders’ equity |
(2,493,130)
|
(3,060,519)
|
|
|
Total liabilities and stockholders’ equity |
$ (4,822,571)
|
$ (4,969,336)
|
|
|