Risk Concentration (Details) - Customer Concentration Risk [Member] - Sales Revenue, Net [Member]	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Western Refining, Inc. [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	31.20%	28.80%	31.50%	29.10%
Kroger [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	20.50%	24.10%	20.80%	24.20%
Western Refining, Retail Business [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	23.20%	26.30%	23.40%	26.00%