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LONG-TERM DEBT (Narrative) (Details) - USD ($) | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Jun. 03, 2019 | Dec. 31, 2018
Debt Instrument [Line Items] |  |  |  |  |  |
Debt issuance costs, net | $ 26,052,000 |  | $ 26,052,000 |  |  | $ 30,733,000
Capitalized interest expense, undeveloped properties | 1,000,000.0 | $ 1,600,000 | 2,800,000 | $ 4,000,000.0 |  |
Gain on debt extinguishment | (23,600,000) | $ 0 | (23,600,000) | $ 0 |  |
Revolving Credit Facility |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Aggregate principal amount | 104,400,000 |  | 104,400,000 |  |  |
Repurchase amount | 80,300,000 |  | 80,300,000 |  |  |
Gain on debt extinguishment |  |  | (23,600,000) |  |  |
Construction loan |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Debt issuance costs, net | 100,000 |  | 100,000 |  |  |
6.000% senior unsecured notes due 2024 | Senior notes |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Long-term debt | $ 630,796,000 |  | $ 630,796,000 |  |  | 650,000,000
Stated interest rate, percent | 6.00% |  | 6.00% |  |  |
Debt issuance costs, net | $ 7,500,000 |  | $ 7,500,000 |  |  |
Aggregate principal amount | 19,200,000 |  | 19,200,000 |  |  |
6.625% senior unsecured notes due 2023 | Senior notes |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Long-term debt | $ 340,000,000 |  | $ 340,000,000 |  |  | 350,000,000
Stated interest rate, percent | 6.625% |  | 6.625% |  |  |
Debt issuance costs, net | $ 3,600,000 |  | $ 3,600,000 |  |  |
Aggregate principal amount | 10,000,000.0 |  | 10,000,000.0 |  |  |
6.375% senior unsecured notes due 2025 | Senior notes |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Long-term debt | $ 577,268,000 |  | $ 577,268,000 |  |  | 600,000,000
Stated interest rate, percent | 6.375% |  | 6.375% |  |  |
Debt issuance costs, net | $ 10,800,000 |  | $ 10,800,000 |  |  |
Aggregate principal amount | 22,700,000 |  | 22,700,000 |  |  |
6.375% senior unsecured notes due 2026 | Senior notes |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Long-term debt | $ 397,529,000 |  | $ 397,529,000 |  |  | 450,000,000
Stated interest rate, percent | 6.375% |  | 6.375% |  |  |
Debt issuance costs, net | $ 4,000,000.0 |  | $ 4,000,000.0 |  |  |
Aggregate principal amount | 52,500,000 |  | $ 52,500,000 |  |  |
Nova Scotia, Amegy, KeyBank | Revolving credit agreement |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Credit facility interest rate at the eurodollar rate |  |  | 3.52% |  |  |
Nova Scotia, Amegy, KeyBank | Revolving credit agreement | Revolving credit agreement |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Borrowing base |  |  |  |  | $ 1,400,000,000 |
Elected commitment amount |  |  |  |  | $ 1,000,000,000.0 |
Long-term debt | 135,000,000 |  | $ 135,000,000 |  |  | $ 45,000,000
Remaining borrowing capacity | 616,400,000 |  | 616,400,000 |  |  |
Nova Scotia, Amegy, KeyBank | Letter of credit | Revolving credit agreement |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |
Credit facility outstanding | $ 248,600,000 |  | $ 248,600,000 |  |  |

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