Major Customers (Details) (Western Refining, Inc. [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Western Refining, Inc. [Member]
Revenue, Major Customer [Line Items]
Revenue, Affiliate Percentage	$ 0.94	$ 0.82	$ 0.71