Quarterly report pursuant to Section 13 or 15(d)

Accounts Receivable and Revenues from Contracts with Customers - Revenue from Contracts with Customers (Details)

v3.10.0.1
Accounts Receivable and Revenues from Contracts with Customers - Revenue from Contracts with Customers (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Gathering, processing and transportation $ 4,928 $ 2,399 $ 12,861 $ 7,505
Net Income (Loss) Available to Common Stockholders, Basic 16,276 (5,947) 24,050 43,463
Calculated under Revenue Guidance in Effect before Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Gathering, processing and transportation 5,482   14,431  
Net Income (Loss) Available to Common Stockholders, Basic 16,276   24,050  
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Gathering, processing and transportation (554)   (1,570)  
Net Income (Loss) Available to Common Stockholders, Basic 0   0  
Oil and Gas, Exploration and Production [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 117,059 29,963 290,033 92,387
Oil and Gas, Exploration and Production [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 117,059   290,033  
Oil and Gas, Exploration and Production [Member] | Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 0   0  
Oil and Condensate [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 5,976 2,393 14,455 6,738
Oil and Condensate [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 6,530   16,025  
Oil and Condensate [Member] | Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues (554)   (1,570)  
Natural Gas, Production [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 3,768 $ 1,977 10,470 $ 6,200
Natural Gas, Production [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 3,768   10,470  
Natural Gas, Production [Member] | Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 0   0  
Oil and Gas, Refining and Marketing [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 143   388  
Oil and Gas, Refining and Marketing [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues 143   388  
Oil and Gas, Refining and Marketing [Member] | Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Revenues $ 0   $ 0