Annual report pursuant to Section 13 and 15(d)

Acquisitions (Details)

v2.4.0.8
Acquisitions (Details) (USD $)
1 Months Ended 12 Months Ended 0 Months Ended
Feb. 28, 2011
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
May 31, 2013
Nov. 13, 2013
Common Stock [Member]
Public Offering [Member]
Feb. 15, 2013
Common Stock [Member]
Public Offering [Member]
Jan. 07, 2013
Common Stock [Member]
Public Offering [Member]
Dec. 24, 2012
Common Stock [Member]
Public Offering [Member]
Dec. 05, 2011
Common Stock [Member]
Public Offering [Member]
Jul. 15, 2011
Common Stock [Member]
Public Offering [Member]
Mar. 30, 2011
Common Stock [Member]
Public Offering [Member]
Feb. 15, 2013
Utica Shale [Member]
well
acre
Dec. 21, 2012
Utica Shale [Member]
Dec. 18, 2012
Utica Shale [Member]
Dec. 19, 2012
Utica Shale [Member]
acre
Dec. 24, 2012
Utica Shale [Member]
acre
Dec. 17, 2012
Utica Shale [Member]
acre
Business Acquisition [Line Items]                                    
Period allowed for refusal 6 months                                  
Affiliates participation ratio 50.00%                                  
Gas and oil acreage, undeveloped, net                         22,000     7,000 37,000 30,000
Cash price of ownership interest                         $ 220,000,000 $ 70,000,000 $ 302,000,000 $ 372,000,000    
Amount put in escrow         (10,000,000)               33,600,000     53,900,000    
Stock option, portion attributable to underwriters (shares)               900,000 750,000                  
Proceeds from issuance of common stock, net of offering costs   $ 766,495,000 $ 427,091,000 $ 307,154,000   $ 408,000,000 $ 325,800,000   $ 460,700,000 $ 128,000,000 $ 94,700,000 $ 84,300,000 $ 325,800,000       $ 460,700,000  
Existing wells excluded                         14          
Future wells excluded                         16