Annual report pursuant to Section 13 and 15(d)

Acquisitions (Details)

v3.6.0.2
Acquisitions (Details)
 1 Months Ended 12 Months Ended
Aug. 31, 2015
USD ($)
Jun. 29, 2015
USD ($)
a
Jun. 12, 2015
USD ($)
a
well
mi
Mcf
Jun. 09, 2015
USD ($)
a
Dec. 31, 2015
USD ($)
Apr. 30, 2015
USD ($)
a
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Business Acquisition [Line Items]                  
Deductions to cash held in escrow             $ (185,000,000) $ 0 $ 0
Paloma Partners III, LLC                  
Business Acquisition [Line Items]                  
Purchase price $ 302,300,000         $ 301,900,000      
Net nonproducing oil and gas acreage (in acres) | a           24,000      
Amount put in escrow $ 30,100,000         $ 75,000,000      
American Energy - Utica, LLC                  
Business Acquisition [Line Items]                  
Purchase price   $ 405,400,000              
Amount put in escrow     $ 67,100,000            
Cash, net of purchase price adjustments   405,000,000 405,029,000            
Deductions to cash held in escrow         $ 2,400,000        
Goodwill     0            
Bargain purchase gain     0            
Belmont And Jefferson Counties, Ohio | American Energy - Utica, LLC                  
Business Acquisition [Line Items]                  
Purchase price       $ 68,200,000          
Gross and net acquired oil and gas acreage (in acres) | a       6,198          
Monroe County, Ohio | American Energy - Utica, LLC                  
Business Acquisition [Line Items]                  
Purchase price   $ 18,200,000 $ 319,000,000            
Net nonproducing oil and gas acreage (in acres) | a   1,900 27,228            
Gross oil and gas acreage acquired (in acres) | a   4,950 38,965            
Net average per day production volume (MMcf) | Mcf     14,600            
Gross number of wells acquired | well     18            
Net number of wells acquired | well     11.3            
Length of gas gathering transportation | mi     11            
Number of well pad locations | well     4