Annual report pursuant to Section 13 and 15(d)

Contingencies (Details)

v3.3.1.900
Contingencies (Details) - USD ($)
1 Months Ended 12 Months Ended
Sep. 30, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Loss Contingencies [Line Items]        
Litigation Settlement, Amount $ 18,000,000      
Insurance Recoveries   $ 10,015,000 $ 0 $ 0
Cash, Uninsured Amount   112,000,000    
Maximum        
Loss Contingencies [Line Items]        
Cash, FDIC Insured Amount   $ 250,000    
Shell Trading Company | Oil and condensate sales        
Loss Contingencies [Line Items]        
Percentage Of Production Sold   90.00% 99.00% 99.00%
Marathon Oil Corporation | Oil and condensate sales        
Loss Contingencies [Line Items]        
Percentage Of Production Sold   10.00%    
Markwest Utica | Natural Gas Liquids        
Loss Contingencies [Line Items]        
Percentage Of Production Sold   76.00% 100.00% 100.00%
British Petroleum | Natural Gas Liquids        
Loss Contingencies [Line Items]        
Percentage Of Production Sold     40.00%  
DTE Energy Trading Inc | Natural Gas Liquids        
Loss Contingencies [Line Items]        
Percentage Of Production Sold     32.00%  
Antero Resources | Natural Gas Liquids        
Loss Contingencies [Line Items]        
Percentage Of Production Sold   24.00%    
Interstate Gas | Natural Gas Liquids        
Loss Contingencies [Line Items]        
Percentage Of Production Sold       17.00%
Interstate Gas | Natural Gas, Per Thousand Cubic Feet        
Loss Contingencies [Line Items]        
Percentage Of Production Sold   79.00%    
Sequent | Natural Gas Liquids        
Loss Contingencies [Line Items]        
Percentage Of Production Sold       32.00%
Sequent | Natural Gas, Per Thousand Cubic Feet        
Loss Contingencies [Line Items]        
Percentage Of Production Sold   14.00%    
Hess | Natural Gas Liquids        
Loss Contingencies [Line Items]        
Percentage Of Production Sold     19.00% 31.00%
Hess | Natural Gas, Per Thousand Cubic Feet        
Loss Contingencies [Line Items]        
Percentage Of Production Sold   5.00%