Concentration Risk (Details) - Customer Concentration Risk [Member] - Sales Revenue, Net [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Western Refining, Inc. [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage	31.60%	30.20%	28.90%
Western Refining, Retail Business [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage	23.30%	26.40%	23.60%
Kroger [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage	20.10%	23.50%	23.00%