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Summary of Significant Accounting Policies (Tables)
12 Months Ended
Dec. 31, 2014
Accounting Policies [Abstract]  
Property Plant And Equipment Estimated Useful Life
We compute depreciation of property, plant, and equipment using the straight-line method, based on the estimated useful life of each asset as follows: 
Assets
Lives in Years
Refining
8 to 47
Logistics
3 to 30
Retail
14 to 18
Corporate
3 to 7
Software
3