Concentration Risk (Details) - Customer Concentration Risk [Member] - Sales Revenue, Net [Member]	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Western Refining, Inc. [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage	30.20%	28.90%	25.90%
Western Refining, Retail Business [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage	23.40%	23.60%	24.20%
Kroger [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage	23.50%	23.00%	27.10%