Acquisitions (Narrative) (Details) (USD $) In Millions, unless otherwise specified		9 Months Ended
	Jul. 20, 2011	Sep. 30, 2012 Gulf Of Mexico Crude Oil Pipeline Systems [Member]	Jan. 03, 2012 Gulf Of Mexico Crude Oil Pipeline Systems [Member]	Aug. 09, 2011 Fmt Black Oil Barge Transportation Business [Member] Barges push_boats	Aug. 09, 2011 Fmt Black Oil Barge Transportation Business Fuel Inventory And Other Cost [Member]	Jan. 03, 2012 FMT Lease [Member]	Aug. 09, 2011 FMT Lease [Member] Barges	Jan. 03, 2012 Genesis Energy Interest In Poseidon [Member]	Jan. 03, 2012 Genesis Energy Interest In GOPL [Member]	Jan. 03, 2012 Genesis Energy Interest In Odyssey [Member]	Jan. 03, 2012 GOPL Interest In Eugene Island Crude Oil Pipeline System [Member]	Jan. 03, 2012 GOPL Interest In Two Small Offshore Pipelines [Member] Other Offshore Pipelines [Member] push_boats	Sep. 30, 2012 Poseidon [Member] mi	Sep. 30, 2012 Eugene Island Pipeline System [Member] mi in	Sep. 30, 2012 Odyssey [Member] mi	Sep. 30, 2012 Maximum [Member] Poseidon [Member] in	Sep. 30, 2012 Maximum [Member] Odyssey [Member] in	Sep. 30, 2012 Minimum [Member] Poseidon [Member] in	Sep. 30, 2012 Minimum [Member] Odyssey [Member] in
Business Acquisition [Line Items]
Percentage of equity interest acquired								28.00%	100.00%	29.00%	23.00%	100.00%
Effective date of acquisition		January 2012
Purchase price, net of post-closing adjustments of acquired entity			$ 205.6	$ 143.5	$ 2.5	$ 30.6
Number of small offshore pipelines acquired												2
Pipeline capacity, barrels per day													400,000	200,000	300,000
Pipeline length, in miles													367	183	120
Pipeline diameter, in inches														20		24	20	16	12
Business Acquisition, Barges Acquired				30			7
Business Acquisition, Push Boats Acquired				14
Equity Issuance, Amount	$ 185