Description of Business and Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2009	Dec. 31, 2010	Dec. 31, 2011 SLC Pipeline [Member] mi	Mar. 01, 2009 SLC Pipeline [Member] mi
Other Ownership Interests [Line Items]
Ownership Percentage by parent, Controlling Interest	42.00%
General partner interest	2.00%	2.00%
Accrual for Environmental Loss Contingencies	$ 1,000,000		$ 300,000
Equity Method Investment, Ownership Percentage				25.00%	25.00%
Crude Oil Pipeline, Length				95	95
Excess Acquisition Costs, Not Recognized due to Common Control	295,000,000
Cash and Cash Equivalents, Original Maturities	3 months
Equity Method Investment, Underlying Equity in Net Assets				60,900,000
Equity Method Investments	25,302,000		25,437,000	25,300,000
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity				$ 35,600,000