v3.4.0.3
Related-Party Transactions Related-Party Transactions, Summary of Transactions Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended
May. 13, 2016
Apr. 20, 2016
Mar. 31, 2016
Dec. 31, 2015
Mar. 31, 2015
Related Party Transactions          
Concentration risk, percentage     56.00%   56.00%
Imbalance settlement gains     $ 1   $ 2
Reimbursements from Tesoro     6   $ 6
Cash distributions per unit (dollars per unit)       $ 0.78  
Distribution declared (including IDRs)     50    
Omnibus Agreement          
Related Party Transactions          
Payment for Administrative Fees     9    
Secondment and Logistics Services Agreement          
Related Party Transactions          
Long-term Purchase Commitment, Amount     $ 2    
Subsequent Event          
Related Party Transactions          
Declaration date   Apr. 20, 2016      
Cash distributions per unit (dollars per unit)   $ 0.81      
Distribution declared (including IDRs) $ 59