Description of Business and Presentation of Financial Statements (Details) (USD $)	1 Months Ended		3 Months Ended							12 Months Ended						12 Months Ended				12 Months Ended
	Dec. 31, 2011		Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010		Jun. 30, 2012 SLC Pipeline [Member] mi	Dec. 31, 2011 UNEV Pipeline [Member]	Dec. 31, 2012 UNEV Pipeline [Member]	Jul. 12, 2012 UNEV Pipeline [Member] in mi	Jun. 30, 2012 UNEV Pipeline [Member]	Dec. 31, 2012 Other Fixed Assets [Member] Minimum [Member]	Dec. 31, 2012 Other Fixed Assets [Member] Maximum [Member]	Dec. 31, 2012 Pipelines [Member] Minimum [Member]	Dec. 31, 2012 Pipelines [Member] Maximum [Member]	Dec. 31, 2012 Terminal Facilities and Tankage [Member] [Member] Minimum [Member]	Dec. 31, 2012 Terminal Facilities and Tankage [Member] [Member] Maximum [Member]
Other Ownership Interests [Line Items]
Ownership percentage, controlling interest			44.00%		42.00%					44.00%
General partner interest										2.00%
Equity method investment, ownership percentage															25.00%		75.00%		75.00%
Crude Oil Pipeline, Length															95			400
Excess Acquisition Costs, Not Recognized due to Common Control			$ 305,600,000							$ 305,600,000
Property, Plant and Equipment, Useful Life																				5 years	10 years	25 years	32 years	15 years	25 years
Equity Method Investment, Underlying Equity in Net Assets			60,000,000							60,000,000
Description Of Pipeline Acquired																		12
Business Acquisitions, Pre Acquisition Cost	3,800,000
Business Acquisitions, Limited partners interest in net income										71,702,000	62,993,000	[1]	44,239,000	[1]
Limited partners’ per unit interest in earnings—basic and diluted:	$ 0		$ 0.37	$ 0.32	$ 0.30	$ 0.30	$ 0	$ 0	$ 0	$ 1.29	$ 1.38	[1]	$ 1.00	[1]		$ 0.08
Equity Method Investments	25,302,000	[1]	25,041,000							25,041,000	25,302,000	[1]
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity			35,000,000							35,000,000
Asset Retirement Obligation	3,600,000		5,600,000							5,600,000	3,600,000
Asset Retirement Obligation, Revision of Estimate										2,900,000
Minimum Annualized Payments Receivable			256,700,000							256,700,000
Accrual for Environmental Loss Contingencies	$ 2,700,000		$ 3,000,000							$ 3,000,000	$ 2,700,000

[1] (1) Restated as described in Note 2.