Acquisitions (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	6 Months Ended	0 Months Ended	6 Months Ended
	Jan. 31, 2012 Nettleton Pipeline [Member]	Jun. 30, 2013 Nettleton Pipeline [Member]	Feb. 07, 2012 Big Sandy Terminal [Member]	Jun. 30, 2013 Big Sandy Terminal [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Jan. 31, 2012		Feb. 07, 2012
Business Acquisition, Cost of Acquired Entity, Cash Paid	$ 12.3		$ 11.0