Acquisitions (Narrative) (Details) (USD $)	0 Months Ended		1 Months Ended	12 Months Ended						1 Months Ended		1 Months Ended				1 Months Ended
	Sep. 16, 2013	Mar. 28, 2012	Jul. 31, 2011	Dec. 31, 2013 Barges Boats	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2013	Jul. 22, 2013 Barges Tug_Boats	Jan. 31, 2012 Gulf Of Mexico Crude Oil Pipeline Systems [Member]	Dec. 31, 2013 Gulf Of Mexico Crude Oil Pipeline Systems [Member]	Aug. 31, 2011 FMT Black Oil Barge Transportation Business [Member]	Aug. 09, 2011 FMT Black Oil Barge Transportation Business [Member] Barge push_boats	Jan. 03, 2012 FMT Lease [Member]	Aug. 09, 2011 FMT Black Oil Barge Transportation Business Fuel Inventory And Other Cost [Member]	Nov. 30, 2011 Garco Refinery [Member] mi	Nov. 30, 2011 Garco Refinery Petroleum Inventories [Member]	Aug. 09, 2011 FMT Lease [Member] FMT Black Oil Barge Transportation Business [Member] Barge	Dec. 31, 2013 Poseidon Oil Pipeline Company, L.L.C. [Member]	Jan. 03, 2012 Poseidon Oil Pipeline Company, L.L.C. [Member]	Jan. 03, 2012 Marathon Offshore Pipeline, LLC [Member]	Dec. 31, 2013 Odyssey Pipeline L.L.C. [Member]	Jan. 03, 2012 Odyssey Pipeline L.L.C. [Member]	Dec. 31, 2013 Eugene Island Pipeline System [Member]	Dec. 31, 2013 Two Offshore Smaller Pipelines [Member] Pipelines	Dec. 31, 2013 CHOPS [Member]	Nov. 30, 2011 Minimum [Member] Garco Refinery [Member] in	Nov. 30, 2011 Maximum [Member] Garco Refinery [Member] in	Dec. 31, 2013 Amended Facility [Member]
Business Acquisition [Line Items]
Ownership percentage																90.00%			28.00%	28.00%	100.00%	29.00%	29.00%	23.00%	100.00%	50.00%
Number of piepelines																									2
Effective date of acquisition										Jan. 03, 2012		Aug. 01, 2011				Nov. 01, 2011
Significant Acquisitions and Disposals, Acquisition Costs or Sale Proceeds											$ 205,576,000		$ 143,500,000	$ 30,900,000	$ 2,500,000	$ 20,000,000	$ 1,300,000
Number of barges acquired									9				30					7
Business Acquisition, Tug Boats Acquired									9
NumberOfBarges				54
Number of push boats acquired													14
Proceeds received from offering, net of costs	263,574,000	169,421,000	184,969,000
Pipeline capacity, barrels per day																3,500
Pipeline length, in miles																300
Pipeline diameter, in inches																											3	6
Price per share of common units issued	$ 47.51	$ 30.80	$ 26.30					$ 0
Proceeds from issuance of senior unsecured notes, including premium				350,000,000	101,000,000	0
Cash paid for acquisition				230,880,000	205,576,000	163,673,000
Interest expense							(35,771,000)
Transaction costs related to business acquisition									230,900,000
NumberOfBoats				23
Line of Credit Facility, Maximum Borrowing Capacity																													$ 1,000,000,000
Property, Plant and Equipment, Estimated Useful Lives				25