Annual report pursuant to Section 13 and 15(d)

Acquisitions (Details)

v3.3.1.900
Acquisitions (Details)
 1 Months Ended 3 Months Ended 12 Months Ended 21 Months Ended
Aug. 31, 2015
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Jun. 29, 2015
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Jun. 12, 2015
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mi
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Jun. 09, 2015
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Apr. 21, 2015
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Mar. 20, 2014
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Nov. 13, 2013
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Feb. 15, 2013
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Apr. 30, 2015
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Feb. 28, 2011
Dec. 31, 2015
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Sep. 30, 2015
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Jun. 30, 2015
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Mar. 31, 2015
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Dec. 31, 2014
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Sep. 30, 2014
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Jun. 30, 2014
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Mar. 31, 2014
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Dec. 31, 2015
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Dec. 31, 2014
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Dec. 31, 2013
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Dec. 31, 2015
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Feb. 28, 2014
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Business Acquisition [Line Items]                                              
Proceeds from issuance of common stock, net of offering costs and exercise of stock options     $ 479,700,000   $ 501,800,000                           $ 981,568,000 $ 689,000 $ 766,495,000    
Revenues                     $ 190,319,000 $ 230,569,000 $ 112,270,000 $ 176,317,000 $ 267,697,000 $ 170,804,000 $ 114,736,000 $ 118,029,000 709,475,000 671,266,000 262,753,000    
Lease operating expenses                                     69,475,000 52,191,000 26,703,000    
Period allowed for refusal                   6 months                          
Affiliates participation ratio                   50.00%                          
Gas And Oil Area, Gross | a   4,950                                          
Deductions to cash held in escrow                                     8,000 $ 8,000 $ 8,000    
Common Stock | Public Offering                                              
Business Acquisition [Line Items]                                              
Proceeds from issuance of common stock, net of offering costs and exercise of stock options             $ 408,000,000 $ 325,800,000                              
Utica Shale                                              
Business Acquisition [Line Items]                                              
Gas and oil acreage, undeveloped, net | a                                             8,000
Purchase price                                     182,000,000        
Cash, net of purchase price adjustments           $ 179,527,000                         179,500,000        
Revenues                                           $ 6,400,000  
Lease operating expenses                                           $ 1,000,000  
Goodwill, Acquired During Period                                     0        
Paloma Partners III, LLC                                              
Business Acquisition [Line Items]                                              
Amount put in escrow $ 30,100,000               $ 75,000,000                            
Purchase price $ 302,300,000               $ 301,900,000                            
Gas And Oil Area, Net | a                 24,000                            
American Energy - Utica, LLC                                              
Business Acquisition [Line Items]                                              
Amount put in escrow       $ 67,100,000                                      
Purchase price   $ 405,400,000                                          
Cash, net of purchase price adjustments   405,000,000 $ 405,029,000                                        
Deductions to cash held in escrow                                     $ 2,400,000        
Goodwill, Acquired During Period       $ 0                                      
Belmont And Jefferson Counties, Ohio                                              
Business Acquisition [Line Items]                                              
Gas And Oil Area, Gross And Net | a       6,198                                      
Purchase price       $ 68,200,000                                      
Monroe County, Ohio                                              
Business Acquisition [Line Items]                                              
Gas And Oil Area, Net | a     27,228                                        
Gas And Oil Area, Gross | a     38,965                                        
Monroe County, Ohio | American Energy - Utica, LLC                                              
Business Acquisition [Line Items]                                              
Purchase price   $ 18,200,000 $ 319,000,000                                        
Gas And Oil Area, Net | a   1,900                                          
Oil And Gas Delivery Commitments And Contracts, Daily Production, Volume | MMcf     14.6                                        
Productive Oil And Gas Wells, Number Of Wells, Gross | well     18                                        
Productive Oil And Gas Wells, Number Of Wells, Net | well     11.3                                        
Gas Gathering, Transportation, Length | mi     11                                        
Number Of Locations For Productive Wells | well     4