Concentration Risk (Details) - Customer Concentration Risk [Member] - Sales Revenue, Net [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Western Refining, Inc. [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	31.20%	30.50%	29.70%	28.70%
Kroger [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	23.30%	22.00%	23.90%	23.40%
Western Refining, Retail Business [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	25.10%	24.20%	23.60%	23.20%