v3.5.0.2
Commitments and Contingencies (Details) - USD ($)
$ in Millions
6 Months Ended 12 Months Ended
Apr. 15, 2016
Mar. 29, 2016
Mar. 22, 2016
Jan. 30, 2014
May 01, 2012
Jun. 30, 2016
Dec. 31, 2015
Dec. 02, 2014
Changes in Environmental Liabilities                
Accruals for environmental expenditures           $ 24 $ 33  
Tioga Crude Oil Pipeline Release                
Changes in Environmental Liabilities                
Accruals for environmental expenditures           19 27  
Environmental liability insurance deductible           1    
Environmental liabilities insurance coverage limit           25    
Estimated Environmental Remediation Expense             66  
Total remediation costs in excess of insurance             $ (41)  
Questar Gas Company v. QEP Field Services Company                
Changes in Environmental Liabilities                
Loss Contingency, Settlement Agreement, Date     March 22, 2016          
Payments for Legal Settlements           15    
Complaint filing date         May 1, 2012      
Liability for estimated damages               $ 21
Gain (Loss) Related to Litigation Settlement           $ 6    
XTO Energy Inc. v. QEP Field Services Company                
Changes in Environmental Liabilities                
Loss Contingency, Settlement Agreement, Date   March 29, 2016            
Litigation Settlement, Amount $ 22              
Complaint filing date       January 30, 2014        
Proceeds from Legal Settlements $ 21