Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Additional Information (Details)

v3.10.0.1
Long-Term Debt - Additional Information (Details)
1 Months Ended 12 Months Ended
May 21, 2018
USD ($)
Nov. 21, 2017
May 04, 2017
USD ($)
bank
Dec. 21, 2016
USD ($)
Oct. 14, 2016
USD ($)
Jan. 31, 2016
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Nov. 28, 2018
USD ($)
Oct. 11, 2017
USD ($)
May 03, 2017
USD ($)
Mar. 29, 2017
USD ($)
Jun. 04, 2015
USD ($)
Apr. 21, 2015
USD ($)
Debt Instrument [Line Items]                              
Long-tern debt             $ 2,118,149,000                
Deferred finance costs             30,733,000 $ 34,781,000              
Capitalized interest costs             4,470,000 9,470,000 $ 9,148,000            
Revolving credit agreement                              
Debt Instrument [Line Items]                              
Debt issued               0              
Construction loans                              
Debt Instrument [Line Items]                              
Debt issued             23,149,000 23,724,000              
Oil and gas properties                              
Debt Instrument [Line Items]                              
Capitalized interest costs             $ 4,500,000 $ 9,500,000              
Nova Scotia, Amegy, KeyBank | Revolving credit agreement                              
Debt Instrument [Line Items]                              
Weight average interest rate             4.23%                
Nova Scotia, Amegy, KeyBank | Base Rate | Minimum                              
Debt Instrument [Line Items]                              
Stated interest rate             0.25%                
Nova Scotia, Amegy, KeyBank | Base Rate | Maximum                              
Debt Instrument [Line Items]                              
Stated interest rate             1.25%                
Nova Scotia, Amegy, KeyBank | Federal Funds Rate                              
Debt Instrument [Line Items]                              
Basis spread on variable rate             0.50%                
Nova Scotia, Amegy, KeyBank | Eurodollar                              
Debt Instrument [Line Items]                              
Basis spread on variable rate             1.00%                
Nova Scotia, Amegy, KeyBank | Eurodollar | Minimum                              
Debt Instrument [Line Items]                              
Stated interest rate             1.25%                
Nova Scotia, Amegy, KeyBank | Eurodollar | Maximum                              
Debt Instrument [Line Items]                              
Stated interest rate             2.25%                
InterBank | Revolving credit agreement | Construction loans                              
Debt Instrument [Line Items]                              
Maximum borrowing capacity                           $ 24,500,000  
Stated interest rate                           4.50%  
InterBank | Letter of credit | Construction loans                              
Debt Instrument [Line Items]                              
Required minimum down payment percentage           30.00%                  
Deferred finance costs             $ 100,000                
Debt issued             $ 23,100,000                
Amended and Restated Credit Agreement | Maximum                              
Debt Instrument [Line Items]                              
Debt covenant ratio for future EBITDAX             4.00                
Amended and Restated Credit Agreement | Revolving credit agreement                              
Debt Instrument [Line Items]                              
Debt covenant ratio for EBITDAX             3.00                
Amended and Restated Credit Agreement | Nova Scotia, Amegy, KeyBank | Revolving credit agreement                              
Debt Instrument [Line Items]                              
Maximum borrowing capacity             $ 1,500,000,000                
Amended and Restated Credit Agreement | Nova Scotia, Amegy, KeyBank | Revolving credit agreement                              
Debt Instrument [Line Items]                              
Borrowing base $ 1,400,000,000.0   $ 1,000,000,000.0       1,200,000,000.0         $ 700,000,000.0      
Minimum acquisition payment limit                         $ 50,000,000.0    
Minimum disposition of property limit                         $ 50,000,000.0    
Number of banks added to syndicate | bank     5                        
Increase (decrease) in interest rate (0.25%) 0.50%                          
Debt issued             45,000,000                
Amended and Restated Credit Agreement | Nova Scotia, Amegy, KeyBank | Letter of credit                              
Debt Instrument [Line Items]                              
Long-term line of credit outstanding             316,600,000                
Line of credit facility, elected commitment $ 1,000,000,000.0           1,000,000,000.0     $ 1,000,000,000.0          
Future borrowings available             638,400,000                
Disposition costs, maximum expenses allowed             $ 3,000,000.0                
7.75% Senior Notes Due 2020 | Senior notes                              
Debt Instrument [Line Items]                              
Stated interest rate             7.75% 7.75%              
6.625% Senior Notes Due 2023 | Senior notes                              
Debt Instrument [Line Items]                              
Stated interest rate             6.625% 6.625%             6.625%
Long-tern debt                             $ 343,600,000
Aggregate principal amount                             $ 350,000,000.0
Deferred finance costs             $ 4,400,000                
Debt issued             $ 350,000,000 $ 350,000,000              
6.000% Senior Notes Due 2024 | Senior notes                              
Debt Instrument [Line Items]                              
Stated interest rate         6.00%   6.00% 6.00%              
Aggregate principal amount         $ 650,000,000.0                    
Proceeds from issuance of Senior notes         $ 638,900,000                    
Deferred finance costs             $ 8,700,000                
Debt issued             $ 650,000,000 $ 650,000,000              
6.375% Senior Notes Due 2025 | Senior notes                              
Debt Instrument [Line Items]                              
Stated interest rate       6.375%     6.375% 6.375%              
Aggregate principal amount       $ 600,000,000                      
Proceeds from issuance of Senior notes       $ 584,700,000                      
Deferred finance costs             $ 12,500,000                
Debt issued             $ 600,000,000 $ 600,000,000              
6.375% Senior Notes Due 2026 | Senior notes                              
Debt Instrument [Line Items]                              
Stated interest rate             6.375% 6.375%     6.375%        
Long-tern debt                     $ 444,100,000        
Aggregate principal amount                     $ 450,000,000        
Deferred finance costs             $ 5,000,000                
Debt issued             $ 450,000,000 $ 450,000,000