Quarterly report pursuant to Section 13 or 15(d)

LONG-TERM DEBT (Narrative) (Details)

v3.19.2
LONG-TERM DEBT (Narrative) (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Jun. 03, 2019
Dec. 31, 2018
Debt Instrument [Line Items]            
Capitalized interest expense, undeveloped properties $ 1,000,000.0 $ 1,500,000 $ 1,800,000 $ 2,400,000    
Debt issuance costs, net 28,426,000   28,426,000     $ 30,733,000
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 $ 650,000,000   $ 650,000,000     650,000,000
Stated interest rate, percent 6.00%   6.00%      
Debt issuance costs, net $ 8,100,000   $ 8,100,000      
6.625% senior unsecured notes due 2023 | Senior notes            
Debt Instrument [Line Items]            
Long-term debt $ 350,000,000   $ 350,000,000     350,000,000
Stated interest rate, percent 6.625%   6.625%      
Debt issuance costs, net $ 4,000,000.0   $ 4,000,000.0      
6.375% senior unsecured notes due 2025 | Senior notes            
Debt Instrument [Line Items]            
Long-term debt $ 600,000,000   $ 600,000,000     600,000,000
Stated interest rate, percent 6.375%   6.375%      
Debt issuance costs, net $ 11,700,000   $ 11,700,000      
6.375% senior unsecured notes due 2026 | Senior notes            
Debt Instrument [Line Items]            
Long-term debt $ 450,000,000   $ 450,000,000     450,000,000
Stated interest rate, percent 6.375%   6.375%      
Debt issuance costs, net $ 4,700,000   $ 4,700,000      
Nova Scotia, Amegy, KeyBank | Revolving credit agreement            
Debt Instrument [Line Items]            
Credit facility interest rate at the eurodollar rate     3.93%      
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 155,000,000   $ 155,000,000     $ 45,000,000
Remaining borrowing capacity 593,500,000   593,500,000      
Nova Scotia, Amegy, KeyBank | Letter of credit | Revolving credit agreement            
Debt Instrument [Line Items]            
Credit facility outstanding $ 251,500,000   $ 251,500,000