Partners' Capital And Distributions (Narrative) (Details) (USD $)	0 Months Ended	1 Months Ended		12 Months Ended
	Dec. 28, 2010	Jul. 31, 2011	Nov. 30, 2010	Dec. 31, 2011 days	Dec. 31, 2010 days	Dec. 31, 2009	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010
Partners Capital And Distributions [Line Items]
General Partners' interest percentage	2.00%
Limited Partners' ownership percentage	98.00%			100.00%
Number of common units issued				71,965,000	64,615,000
Proceeds received from offering, net of costs		$ 184,969,000	$ 118,837,000
Common units, outstanding				71,965,000	64,615,000
Partners' Capital Account, Distribution Per Unit of Limited Partner Interest				$ 0.4400	$ 0.4000	$ 0.3600	$ 0.4275	$ 0.4150	$ 0.4075	$ 0.3875	$ 0.3750	$ 0.3675
Distribution paid per common unit				$ 0.4400	$ 0.4000	$ 0.3600	$ 0.4275	$ 0.4150	$ 0.4075	$ 0.3875	$ 0.3750	$ 0.3675
Cash or stock available for distributions, percent usually distributed				100.00%	100.00%
Days to distribute				45	45
Price per share of common units issued		$ 26.30	$ 23.58
Issuance of common units for cash, net				184,969,000	116,347,000
Contribution of capital			2,500,000		2,500,000	100,000
Capital account percentage			2.00%
Non-cash contributions					76,900,000	14,100,000
Noncash compensation charge					76,923,000	14,104,000
Waiver Units Class 1 [Member]
Partners Capital And Distributions [Line Items]
Waiver units authorized				1,750,000
Waiver Units Class 2 [Member]
Partners Capital And Distributions [Line Items]
Waiver units authorized				1,750,000
Waiver Units Class 3 [Member]
Partners Capital And Distributions [Line Items]
Waiver units authorized				1,750,000
Waiver Units Class 4 [Member]
Partners Capital And Distributions [Line Items]
Waiver units authorized				1,750,000
General Partner Interest [Member]
Partners Capital And Distributions [Line Items]
General Partners' interest percentage	2.00%
Genesis Crude Oil, L.P. [Member]
Partners Capital And Distributions [Line Items]
General Partners' interest percentage	0.01%
Class A [Member]
Partners Capital And Distributions [Line Items]
Common units, outstanding				71,925,065
Class B [Member]
Partners Capital And Distributions [Line Items]
Common units, outstanding				39,997
Waiver Units [Member]
Partners Capital And Distributions [Line Items]
Partners' Capital Account, Distribution Per Unit of Limited Partner Interest				$ 0.44
Distribution paid per common unit				$ 0.44
Waiver units authorized	7,000,000			6,949,004
Class One [Member]
Partners Capital And Distributions [Line Items]
Conversion feature threshold, quarterly distribution, minimum, per unit				$ 0.43
Conversion feature, minimum distribution coverage ratio				1.1
Class Two [Member]
Partners Capital And Distributions [Line Items]
Conversion feature threshold, quarterly distribution, minimum, per unit				$ 0.46
Conversion feature, minimum distribution coverage ratio				1.1
Class Three [Member]
Partners Capital And Distributions [Line Items]
Conversion feature threshold, quarterly distribution, minimum, per unit				$ 0.49
Conversion feature, minimum distribution coverage ratio				1.1
Class Four [Member]
Partners Capital And Distributions [Line Items]
Conversion feature threshold, quarterly distribution, minimum, per unit				$ 0.52
Conversion feature, minimum distribution coverage ratio				1.1
Cameron Highway Oil Pipeline Company [Member]
Partners Capital And Distributions [Line Items]
Number of common units issued			5,175,000
Percentage of equity interest			50.00%
General Partners [Member]
Partners Capital And Distributions [Line Items]
Number of common units issued	27,000,000
General Partners [Member] | Class A [Member]
Partners Capital And Distributions [Line Items]
Number of common units issued	19,960,000
General Partners [Member] | Class B [Member]
Partners Capital And Distributions [Line Items]
Number of common units issued	40,000
FMT Black Oil Barge Transportation Business [Member] | Class A [Member]
Partners Capital And Distributions [Line Items]
Number of common units issued		7,350,000
Proceeds received from offering, net of costs		$ 185,000,000