| CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Tables)
 | 9 Months Ended | 
| Sep. 30, 2020 | 
|---|
| Condensed Financial Information Disclosure [Abstract] |  | 
| CONDENSED CONSOLIDATING BALANCE SHEETS | CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands)  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | September 30, 2020 |  
|  | Parent |  | Guarantors |  | Non-Guarantors |  | Eliminations |  | Consolidated |  
| Assets |  |  |  |  |  |  |  |  |  |  
| Current assets: |  |  |  |  |  |  |  |  |  |  
| Cash and cash equivalents | $ | 43,774 |  |  | $ | 2,197 |  |  | $ | 5,072 |  |  | $ | — |  |  | $ | 51,043 |  |  
| Accounts receivable - oil and natural gas sales | 861 |  |  | 91,582 |  |  | — |  |  | — |  |  | 92,443 |  |  
| Accounts receivable - joint interest and other | 428 |  |  | 14,993 |  |  | — |  |  | — |  |  | 15,421 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Accounts receivable - intercompany | 332,011 |  |  | 73,885 |  |  | — |  |  | (405,896) |  |  | — |  |  
| Prepaid expenses and other current assets | 18,192 |  |  | 32,919 |  |  | 76 |  |  | — |  |  | 51,187 |  |  
| Short-term derivative instruments | 6,245 |  |  | — |  |  | — |  |  | — |  |  | 6,245 |  |  
| Total current assets | 401,511 |  |  | 215,576 |  |  | 5,148 |  |  | (405,896) |  |  | 216,339 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Property and equipment: |  |  |  |  |  |  |  |  |  |  
| Oil and natural gas properties, full-cost accounting | 1,248,836 |  |  | 9,531,593 |  |  | 6,606 |  |  | (730) |  |  | 10,786,305 |  |  
| Other property and equipment | 92,551 |  |  | 51 |  |  | 3,319 |  |  | — |  |  | 95,921 |  |  
| Accumulated depletion, depreciation, amortization and impairment | (1,425,619) |  |  | (7,352,069) |  |  | (2,016) |  |  | — |  |  | (8,779,704) |  |  
| Property and equipment, net | (84,232) |  |  | 2,179,575 |  |  | 7,909 |  |  | (730) |  |  | 2,102,522 |  |  
| Other assets: |  |  |  |  |  |  |  |  |  |  
| Equity investments and investments in subsidiaries | 1,802,762 |  |  | 6,333 |  |  | 16,521 |  |  | (1,809,056) |  |  | 16,560 |  |  
| Long-term derivative instruments | 1,098 |  |  | — |  |  | — |  |  | — |  |  | 1,098 |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Operating lease assets | 2,012 |  |  | — |  |  | — |  |  | — |  |  | 2,012 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Other assets | 28,390 |  |  | 8,638 |  |  | — |  |  | — |  |  | 37,028 |  |  
| Total other assets | 1,834,262 |  |  | 14,971 |  |  | 16,521 |  |  | (1,809,056) |  |  | 56,698 |  |  
| Total assets | $ | 2,151,541 |  |  | $ | 2,410,122 |  |  | $ | 29,578 |  |  | $ | (2,215,682) |  |  | $ | 2,375,559 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| 
Liabilities and Stockholders’ Equity
 |  |  |  |  |  |  |  |  |  |  
| Current liabilities: |  |  |  |  |  |  |  |  |  |  
| Accounts payable and accrued liabilities | $ | 59,543 |  |  | $ | 235,778 |  |  | $ | 38 |  |  | $ | — |  |  | $ | 295,359 |  |  
| Accounts payable - intercompany | 74,733 |  |  | 321,373 |  |  | 9,789 |  |  | (405,895) |  |  | — |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Short-term derivative instruments | 24,164 |  |  | — |  |  | — |  |  | — |  |  | 24,164 |  |  
| Current portion of operating lease liabilities | 1,757 |  |  | — |  |  | — |  |  | — |  |  | 1,757 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Current maturities of long-term debt | 656 |  |  | — |  |  | — |  |  | — |  |  | 656 |  |  
| Total current liabilities | 160,853 |  |  | 557,151 |  |  | 9,827 |  |  | (405,895) |  |  | 321,936 |  |  
| Long-term derivative instruments | 63,803 |  |  | — |  |  | — |  |  | — |  |  | 63,803 |  |  
| Asset retirement obligation - long-term | — |  |  | 62,935 |  |  | — |  |  | — |  |  | 62,935 |  |  
| Uncertain tax position liability | 3,371 |  |  | — |  |  | — |  |  | — |  |  | 3,371 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Non-current operating lease liabilities | 255 |  |  | — |  |  | — |  |  | — |  |  | 255 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Long-term debt, net of current maturities | 2,068,036 |  |  | — |  |  | — |  |  | — |  |  | 2,068,036 |  |  
| Total liabilities | 2,296,318 |  |  | 620,086 |  |  | 9,827 |  |  | (405,895) |  |  | 2,520,336 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Stockholders’ equity: |  |  |  |  |  |  |  |  |  |  
| Common stock | 1,607 |  |  | — |  |  | — |  |  | — |  |  | 1,607 |  |  
| Paid-in capital | 4,212,241 |  |  | 4,291,981 |  |  | 267,560 |  |  | (4,559,541) |  |  | 4,212,241 |  |  
| Accumulated other comprehensive loss | (51,329) |  |  | 3 |  |  | (48,902) |  |  | 48,898 |  |  | (51,330) |  |  
| Accumulated deficit | (4,307,296) |  |  | (2,501,948) |  |  | (198,907) |  |  | 2,700,856 |  |  | (4,307,295) |  |  
| Total stockholders’ equity | (144,777) |  |  | 1,790,036 |  |  | 19,751 |  |  | (1,809,787) |  |  | (144,777) |  |  
| 
Total liabilities and stockholders’ equity
 | $ | 2,151,541 |  |  | $ | 2,410,122 |  |  | $ | 29,578 |  |  | $ | (2,215,682) |  |  | $ | 2,375,559 |  | CONDENSED CONSOLIDATING BALANCE SHEETS (Amounts in thousands) 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | December 31, 2019 |  
|  | Parent |  | Guarantors |  | Non-Guarantor |  | Eliminations |  | Consolidated |  
| Assets |  |  |  |  |  |  |  |  |  |  
| Current assets: |  |  |  |  |  |  |  |  |  |  
| Cash and cash equivalents | $ | 2,768 |  |  | $ | 3,097 |  |  | $ | 195 |  |  | $ | — |  |  | $ | 6,060 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Accounts receivable - oil and natural gas sales | 859 |  |  | 120,351 |  |  | — |  |  | — |  |  | 121,210 |  |  
| Accounts receivable - joint interest and other | 5,279 |  |  | 42,696 |  |  | — |  |  | — |  |  | 47,975 |  |  
| Accounts receivable - intercompany | 1,065,593 |  |  | 843,223 |  |  | — |  |  | (1,908,816) |  |  | — |  |  
| Prepaid expenses and other current assets | 4,047 |  |  | 308 |  |  | 76 |  |  | — |  |  | 4,431 |  |  
| Short-term derivative instruments | 126,201 |  |  | — |  |  | — |  |  | — |  |  | 126,201 |  |  
| Total current assets | 1,204,747 |  |  | 1,009,675 |  |  | 271 |  |  | (1,908,816) |  |  | 305,877 |  |  
| Property and equipment: |  |  |  |  |  |  |  |  |  |  
| Oil and natural gas properties, full-cost accounting, | 1,314,933 |  |  | 9,273,681 |  |  | 7,850 |  |  | (729) |  |  | 10,595,735 |  |  
| Other property and equipment | 92,650 |  |  | 50 |  |  | 4,019 |  |  | — |  |  | 96,719 |  |  
| Accumulated depletion, depreciation, amortization and impairment | (1,418,888) |  |  | (5,808,254) |  |  | (1,518) |  |  | — |  |  | (7,228,660) |  |  
| Property and equipment, net | (11,305) |  |  | 3,465,477 |  |  | 10,351 |  |  | (729) |  |  | 3,463,794 |  |  
| Other assets: |  |  |  |  |  |  |  |  |  |  
| Equity investments and investments in subsidiaries | 3,064,503 |  |  | 6,332 |  |  | 21,000 |  |  | (3,059,791) |  |  | 32,044 |  |  
| Long-term derivative instruments | 563 |  |  | — |  |  | — |  |  | — |  |  | 563 |  |  
| Deferred tax asset | 7,563 |  |  | — |  |  | — |  |  | — |  |  | 7,563 |  |  
| Operating lease assets | 14,168 |  |  | — |  |  | — |  |  | — |  |  | 14,168 |  |  
| Operating lease assets - related parties | 43,270 |  |  | — |  |  | — |  |  | — |  |  | 43,270 |  |  
| Other assets | 10,026 |  |  | 5,514 |  |  | — |  |  | — |  |  | 15,540 |  |  
| Total other assets | 3,140,093 |  |  | 11,846 |  |  | 21,000 |  |  | (3,059,791) |  |  | 113,148 |  |  
| Total assets | $ | 4,333,535 |  |  | $ | 4,486,998 |  |  | $ | 31,622 |  |  | $ | (4,969,336) |  |  | $ | 3,882,819 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| 
Liabilities and Stockholders’ Equity
 |  |  |  |  |  |  |  |  |  |  
| Current liabilities: |  |  |  |  |  |  |  |  |  |  
| Accounts payable and accrued liabilities | $ | 48,006 |  |  | $ | 367,088 |  |  | $ | 124 |  |  | $ | — |  |  | $ | 415,218 |  |  
| Accounts payable - intercompany | 878,283 |  |  | 1,026,249 |  |  | 4,285 |  |  | (1,908,817) |  |  | — |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Short-term derivative instruments | 303 |  |  | — |  |  | — |  |  | — |  |  | 303 |  |  
| Current portion of operating lease liabilities | 13,826 |  |  | — |  |  | — |  |  | — |  |  | 13,826 |  |  
| Current portion of operating lease liabilities - related parties | 21,220 |  |  | — |  |  | — |  |  | — |  |  | 21,220 |  |  
| Current maturities of long-term debt | 631 |  |  | — |  |  | — |  |  | — |  |  | 631 |  |  
| Total current liabilities | 962,269 |  |  | 1,393,337 |  |  | 4,409 |  |  | (1,908,817) |  |  | 451,198 |  |  
| Long-term derivative instruments | 53,135 |  |  | — |  |  | — |  |  | — |  |  | 53,135 |  |  
| Asset retirement obligation - long-term | — |  |  | 58,322 |  |  | 2,033 |  |  | — |  |  | 60,355 |  |  
| Uncertain tax position liability | 3,127 |  |  | — |  |  | — |  |  | — |  |  | 3,127 |  |  
| Non-current operating lease liabilities | 342 |  |  | — |  |  | — |  |  | — |  |  | 342 |  |  
| Non-current operating lease liabilities - related parties | 22,050 |  |  | — |  |  | — |  |  | — |  |  | 22,050 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Long-term debt, net of current maturities | 1,978,020 |  |  | — |  |  | — |  |  | — |  |  | 1,978,020 |  |  
| Total liabilities | 3,018,943 |  |  | 1,451,659 |  |  | 6,442 |  |  | (1,908,817) |  |  | 2,568,227 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Stockholders’ equity: |  |  |  |  |  |  |  |  |  |  
| Common stock | 1,597 |  |  | — |  |  | — |  |  | — |  |  | 1,597 |  |  
| Paid-in capital | 4,207,554 |  |  | 4,171,408 |  |  | 267,557 |  |  | (4,438,965) |  |  | 4,207,554 |  |  
| Accumulated other comprehensive loss | (46,833) |  |  | — |  |  | (44,763) |  |  | 44,763 |  |  | (46,833) |  |  
| Accumulated deficit | (2,847,726) |  |  | (1,136,069) |  |  | (197,614) |  |  | 1,333,683 |  |  | (2,847,726) |  |  
| Total stockholders’ equity | 1,314,592 |  |  | 3,035,339 |  |  | 25,180 |  |  | (3,060,519) |  |  | 1,314,592 |  |  
| 
  Total liabilities and stockholders’ equity
 | $ | 4,333,535 |  |  | $ | 4,486,998 |  |  | $ | 31,622 |  |  | $ | (4,969,336) |  |  | $ | 3,882,819 |  |  | 
| CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS | CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Three months ended September 30, 2020 |  
|  | Parent |  | Guarantors |  | Non-Guarantors |  | Eliminations |  | Consolidated |  
|  |  |  |  |  |  |  |  |  |  |  
| Total revenues | $ | (53,823) |  |  | $ | 189,999 |  |  | $ | — |  |  | $ | — |  |  | $ | 136,176 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Costs and expenses: |  |  |  |  |  |  |  |  |  |  
| Lease operating expenses | (157) |  |  | 15,431 |  |  | — |  |  | — |  |  | 15,274 |  |  
| Production taxes | — |  |  | 4,028 |  |  | — |  |  | — |  |  | 4,028 |  |  
| Midstream gathering and processing expenses | — |  |  | 110,567 |  |  | — |  |  | — |  |  | 110,567 |  |  
| Depreciation, depletion and amortization | 2,265 |  |  | 49,120 |  |  | 166 |  |  | — |  |  | 51,551 |  |  
| Impairment of oil and natural gas properties | — |  |  | 270,874 |  |  | — |  |  | — |  |  | 270,874 |  |  
| General and administrative expenses | 29,454 |  |  | (9,098) |  |  | 168 |  |  | — |  |  | 20,524 |  |  
| Restructuring and liability management | 8,984 |  |  | — |  |  | — |  |  | — |  |  | 8,984 |  |  
| Accretion expense | — |  |  | 774 |  |  | — |  |  | — |  |  | 774 |  |  
| Total Operating Expenses | 40,546 |  |  | 441,696 |  |  | 334 |  |  | — |  |  | 482,576 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| LOSS FROM OPERATIONS | (94,369) |  |  | (251,697) |  |  | (334) |  |  | — |  |  | (346,400) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| OTHER EXPENSE (INCOME): |  |  |  |  |  |  |  |  |  |  
| Interest expense | 34,488 |  |  | (167) |  |  | — |  |  | — |  |  | 34,321 |  |  
| Interest income | (16) |  |  | (36) |  |  | — |  |  | — |  |  | (52) |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Loss from equity method investments and investments in subsidiaries | 251,951 |  |  | — |  |  | 153 |  |  | (251,951) |  |  | 153 |  |  
| Other expense (income) | 172 |  |  | (31) |  |  | — |  |  | — |  |  | 141 |  |  
| Total Other Expense (Income) | 286,595 |  |  | (234) |  |  | 153 |  |  | (251,951) |  |  | 34,563 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| LOSS BEFORE INCOME TAXES | (380,964) |  |  | (251,463) |  |  | (487) |  |  | 251,951 |  |  | (380,963) |  |  
| INCOME TAX EXPENSE | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  
|  |  |  |  |  |  |  |  |  |  |  
| NET LOSS | $ | (380,964) |  |  | $ | (251,463) |  |  | $ | (487) |  |  | $ | 251,951 |  |  | $ | (380,963) |  | CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Three months ended September 30, 2019 |  
|  | Parent |  | Guarantors |  | Non-Guarantor |  | Eliminations |  | Consolidated |  
|  |  |  |  |  |  |  |  |  |  |  
| Total revenues | $ | 27,358 |  |  | $ | 314,388 |  |  | $ | — |  |  | $ | — |  |  | $ | 341,746 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Costs and expenses: |  |  |  |  |  |  |  |  |  |  
| Lease operating expenses | (231) |  |  | 22,704 |  |  | — |  |  | — |  |  | 22,473 |  |  
| Production taxes | 36 |  |  | 6,529 |  |  | — |  |  | — |  |  | 6,565 |  |  
| Midstream gathering and processing expenses | — |  |  | 135,006 |  |  | — |  |  | — |  |  | 135,006 |  |  
| Depreciation, depletion and amortization | 2,686 |  |  | 160,418 |  |  | 166 |  |  | — |  |  | 163,270 |  |  
| Impairment of oil and natural gas properties | — |  |  | 571,442 |  |  | — |  |  | — |  |  | 571,442 |  |  
| General and administrative expenses | 25,757 |  |  | (12,675) |  |  | 116 |  |  | — |  |  | 13,198 |  |  
| Accretion expense | — |  |  | 747 |  |  | — |  |  | — |  |  | 747 |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Total Operating Expenses | 28,248 |  |  | 884,171 |  |  | 282 |  |  | — |  |  | 912,701 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| LOSS FROM OPERATIONS | (890) |  |  | (569,783) |  |  | (282) |  |  | — |  |  | (570,955) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| OTHER EXPENSE (INCOME): |  |  |  |  |  |  |  |  |  |  
| Interest expense | 36,566 |  |  | (1,010) |  |  | — |  |  | — |  |  | 35,556 |  |  
| Interest income | (187) |  |  | (151) |  |  | — |  |  | — |  |  | (338) |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Gain on debt extinguishment | (23,600) |  |  | — |  |  | — |  |  | — |  |  | (23,600) |  |  
| Loss from equity method investments and investments in subsidiaries | 616,348 |  |  | — |  |  | 40 |  |  | (573,306) |  |  | 43,082 |  |  
| Other (income) expense | (1,168) |  |  | 3,362 |  |  | — |  |  | 1,000 |  |  | 3,194 |  |  
| Total Other Expense | 627,959 |  |  | 2,201 |  |  | 40 |  |  | (572,306) |  |  | 57,894 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| LOSS BEFORE INCOME TAXES | (628,849) |  |  | (571,984) |  |  | (322) |  |  | 572,306 |  |  | (628,849) |  |  
| INCOME TAX BENEFIT | (144,047) |  |  | — |  |  | — |  |  | — |  |  | (144,047) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| NET LOSS | $ | (484,802) |  |  | $ | (571,984) |  |  | $ | (322) |  |  | $ | 572,306 |  |  | $ | (484,802) |  | CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Nine months ended September 30, 2020 |  
|  | Parent |  | Guarantors |  | Non-Guarantors |  | Eliminations |  | Consolidated |  
|  |  |  |  |  |  |  |  |  |  |  
| Total revenues | $ | 71,415 |  |  | $ | 550,400 |  |  | $ | — |  |  | $ | — |  |  | $ | 621,815 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Costs and expenses: |  |  |  |  |  |  |  |  |  |  
| Lease operating expenses | (157) |  |  | 47,103 |  |  | — |  |  | — |  |  | 46,946 |  |  
| Production taxes | — |  |  | 12,432 |  |  | — |  |  | — |  |  | 12,432 |  |  
| Midstream gathering and processing expenses | — |  |  | 334,789 |  |  | — |  |  | — |  |  | 334,789 |  |  
| Depreciation, depletion, and amortization | 7,155 |  |  | 186,716 |  |  | 498 |  |  | — |  |  | 194,369 |  |  
| Impairment of oil and gas properties | — |  |  | 1,357,099 |  |  | — |  |  | — |  |  | 1,357,099 |  |  
| General and administrative expenses | 75,214 |  |  | (29,122) |  |  | 454 |  |  | — |  |  | 46,546 |  |  
| Restructuring and liability management | 9,601 |  |  | — |  |  | — |  |  | — |  |  | 9,601 |  |  
| Accretion expense | — |  |  | 2,270 |  |  | — |  |  | — |  |  | 2,270 |  |  
| Total Operating Expenses | 91,813 |  |  | 1,911,287 |  |  | 952 |  |  | — |  |  | 2,004,052 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| LOSS FROM OPERATIONS | (20,398) |  |  | (1,360,887) |  |  | (952) |  |  | — |  |  | (1,382,237) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| OTHER EXPENSE (INCOME): |  |  |  |  |  |  |  |  |  |  
| Interest expense | 100,490 |  |  | (813) |  |  | — |  |  | — |  |  | 99,677 |  |  
| Interest income | (103) |  |  | (179) |  |  | — |  |  | — |  |  | (282) |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Gain on debt extinguishment | (49,579) |  |  | — |  |  | — |  |  | — |  |  | (49,579) |  |  
| Loss from equity method investments and investments in subsidiaries | 1,377,819 |  |  | — |  |  | 341 |  |  | (1,367,173) |  |  | 10,987 |  |  
| Other expense | 3,255 |  |  | 5,984 |  |  | — |  |  | — |  |  | 9,239 |  |  
| Total Other Expense | 1,431,882 |  |  | 4,992 |  |  | 341 |  |  | (1,367,173) |  |  | 70,042 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| LOSS BEFORE INCOME TAXES | (1,452,280) |  |  | (1,365,879) |  |  | (1,293) |  |  | 1,367,173 |  |  | (1,452,279) |  |  
| INCOME TAX EXPENSE | 7,290 |  |  | — |  |  | — |  |  | — |  |  | 7,290 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| NET LOSS | $ | (1,459,570) |  |  | $ | (1,365,879) |  |  | $ | (1,293) |  |  | $ | 1,367,173 |  |  | $ | (1,459,569) |  | CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Amounts in thousands) 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Nine months ended September 30, 2019 |  
|  | Parent |  | Guarantors |  | Non-Guarantor |  | Eliminations |  | Consolidated |  
|  |  |  |  |  |  |  |  |  |  |  
| Total revenues | $ | 493,895 |  |  | $ | 732,763 |  |  | $ | — |  |  | $ | — |  |  | $ | 1,226,658 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Costs and expenses: |  |  |  |  |  |  |  |  |  |  
| Lease operating expenses | 26,918 |  |  | 37,750 |  |  | — |  |  | — |  |  | 64,668 |  |  
| Production taxes | 6,117 |  |  | 16,467 |  |  | — |  |  | — |  |  | 22,584 |  |  
| Midstream gathering and processing expenses | 71,420 |  |  | 311,223 |  |  | — |  |  | — |  |  | 382,643 |  |  
| Depreciation, depletion, and amortization | 201,250 |  |  | 205,183 |  |  | 221 |  |  | — |  |  | 406,654 |  |  
| Impairment of oil and natural gas properties | — |  |  | 571,442 |  |  | — |  |  | — |  |  | 571,442 |  |  
| General and administrative expenses | 51,695 |  |  | (16,933) |  |  | 220 |  |  | — |  |  | 34,982 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Accretion expense | 1,389 |  |  | 1,784 |  |  | — |  |  | — |  |  | 3,173 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Total Operating Expenses | 358,789 |  |  | 1,126,916 |  |  | 441 |  |  | — |  |  | 1,486,146 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| INCOME (LOSS) FROM OPERATIONS | 135,106 |  |  | (394,153) |  |  | (441) |  |  | — |  |  | (259,488) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| OTHER EXPENSE (INCOME): |  |  |  |  |  |  |  |  |  |  
| Interest expense | 109,864 |  |  | (2,269) |  |  | — |  |  | — |  |  | 107,595 |  |  
| Interest income | (454) |  |  | (195) |  |  | — |  |  | — |  |  | (649) |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Gain on debt extinguishment | (23,600) |  |  | — |  |  | — |  |  | — |  |  | (23,600) |  |  
| Loss from equity method investments and investments in subsidiaries | 560,883 |  |  | — |  |  | 379 |  |  | (396,871) |  |  | 164,391 |  |  
| Other (income) expense | (605) |  |  | 3,362 |  |  | — |  |  | 1,000 |  |  | 3,757 |  |  
| Total Other Expense | 646,088 |  |  | 898 |  |  | 379 |  |  | (395,871) |  |  | 251,494 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| LOSS BEFORE INCOME TAXES | (510,982) |  |  | (395,051) |  |  | (820) |  |  | 395,871 |  |  | (510,982) |  |  
| INCOME TAX BENEFIT | (323,378) |  |  | — |  |  | — |  |  | — |  |  | (323,378) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| NET LOSS | $ | (187,604) |  |  | $ | (395,051) |  |  | $ | (820) |  |  | $ | 395,871 |  |  | $ | (187,604) |  |  | 
| CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) | 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Three months ended September 30, 2020 |  
|  | Parent |  | Guarantors |  | Non-Guarantors |  | Eliminations |  | Consolidated |  
|  |  |  |  |  |  |  |  |  |  |  
| Net loss | $ | (380,964) |  |  | $ | (251,463) |  |  | $ | (487) |  |  | $ | 251,951 |  |  | $ | (380,963) |  |  
| Foreign currency translation adjustment | 3,661 |  |  | — |  |  | 3,661 |  |  | (3,661) |  |  | 3,661 |  |  
| Other comprehensive loss | 3,661 |  |  | — |  |  | 3,661 |  |  | (3,661) |  |  | 3,661 |  |  
| Comprehensive loss | $ | (377,303) |  |  | $ | (251,463) |  |  | $ | 3,174 |  |  | $ | 248,290 |  |  | $ | (377,302) |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Three months ended September 30, 2019 |  
|  | Parent |  | Guarantors |  | Non-Guarantor |  | Eliminations |  | Consolidated |  
|  |  |  |  |  |  |  |  |  |  |  
| Net loss | $ | (484,802) |  |  | $ | (571,984) |  |  | $ | (322) |  |  | $ | 572,306 |  |  | $ | (484,802) |  |  
| Foreign currency translation adjustment | (2,064) |  |  | (43) |  |  | (2,021) |  |  | 2,064 |  |  | (2,064) |  |  
|  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Other comprehensive income | (2,064) |  |  | (43) |  |  | (2,021) |  |  | 2,064 |  |  | (2,064) |  |  
| Comprehensive loss | $ | (486,866) |  |  | $ | (572,027) |  |  | $ | (2,343) |  |  | $ | 574,370 |  |  | $ | (486,866) |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Nine months ended September 30, 2020 |  
|  | Parent |  | Guarantors |  | Non-Guarantors |  | Eliminations |  | Consolidated |  
|  |  |  |  |  |  |  |  |  |  |  
| Net loss | $ | (1,459,570) |  |  | $ | (1,365,879) |  |  | $ | (1,293) |  |  | $ | 1,367,173 |  |  | $ | (1,459,569) |  |  
| Foreign currency translation adjustment | (4,497) |  |  | (360) |  |  | (4,137) |  |  | 4,497 |  |  | (4,497) |  |  
| Other comprehensive loss | (4,497) |  |  | (360) |  |  | (4,137) |  |  | 4,497 |  |  | (4,497) |  |  
| Comprehensive loss | $ | (1,464,067) |  |  | $ | (1,366,239) |  |  | $ | (5,430) |  |  | $ | 1,371,670 |  |  | $ | (1,464,066) |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Nine months ended September 30, 2019 |  
|  | Parent |  | Guarantors |  | Non-Guarantor |  | Eliminations |  | Consolidated |  
|  |  |  
| Net loss | $ | (187,604) |  |  | $ | (395,051) |  |  | $ | (820) |  |  | $ | 395,871 |  |  | $ | (187,604) |  |  
| Foreign currency translation adjustment | 5,347 |  |  | 112 |  |  | 5,235 |  |  | (5,347) |  |  | 5,347 |  |  
| Other comprehensive income | 5,347 |  |  | 112 |  |  | 5,235 |  |  | (5,347) |  |  | 5,347 |  |  
| Comprehensive (loss) income | $ | (182,257) |  |  | $ | (394,939) |  |  | $ | 4,415 |  |  | $ | 390,524 |  |  | $ | (182,257) |  |  | 
| CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS | CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Amounts in thousands) 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Nine months ended September 30, 2020 |  
|  | Parent |  | Guarantors |  | Non-Guarantors |  | Eliminations |  | Consolidated |  
|  |  |  |  |  |  |  |  |  |  |  
| Net cash provided by (used in) operating activities | $ | (95,023) |  |  | $ | 290,147 |  |  | $ | 4,442 |  |  | $ | 435 |  |  | $ | 200,001 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Net cash used in investing activities | 351 |  |  | (291,047) |  |  | — |  |  | — |  |  | (290,696) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Net cash (used in) provided by financing activities | 135,678 |  |  | — |  |  | 435 |  |  | (435) |  |  | 135,678 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Net (decrease) increase  in cash, cash equivalents and restricted cash | 41,006 |  |  | (900) |  |  | 4,877 |  |  | — |  |  | 44,983 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Cash, cash equivalents and restricted cash at beginning of period | 2,768 |  |  | 3,097 |  |  | 195 |  |  | — |  |  | 6,060 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Cash, cash equivalents and restricted cash at end of period | $ | 43,774 |  |  | $ | 2,197 |  |  | $ | 5,072 |  |  | $ | — |  |  | $ | 51,043 |  | 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Nine months ended September 30, 2019 |  
|  | Parent |  | Guarantors |  | Non-Guarantor |  | Eliminations |  | Consolidated |  
|  |  |  |  |  |  |  |  |  |  |  
| Net cash (used in) provided by operating activities | $ | (7,604) |  |  | $ | 621,511 |  |  | $ | 3,445 |  |  | $ | 3 |  |  | $ | 617,355 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Net cash provided by (used in) investing activities | 9,178 |  |  | (644,507) |  |  | (3,751) |  |  | 432 |  |  | (638,648) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Net cash (used in) provided by financing activities | (20,880) |  |  | — |  |  | 435 |  |  | (435) |  |  | (20,880) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Net (decrease) increase in cash, cash equivalents and restricted cash | (19,306) |  |  | (22,996) |  |  | 129 |  |  | — |  |  | (42,173) |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Cash, cash equivalents and restricted cash at beginning of period | 25,585 |  |  | 26,711 |  |  | 1 |  |  | — |  |  | 52,297 |  |  
|  |  |  |  |  |  |  |  |  |  |  
| Cash, cash equivalents and restricted cash at end of period | $ | 6,279 |  |  | $ | 3,715 |  |  | $ | 130 |  |  | $ | — |  |  | $ | 10,124 |  |  |