Acquisitions Legacy Frontier (Details) (USD $)	3 Months Ended									12 Months Ended			0 Months Ended	12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011		Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Nov. 09, 2011 Legacy Frontier [Member]	Dec. 31, 2011 Legacy Frontier [Member]	Nov. 09, 2011 Legacy Frontier [Member] Notes Payable, Other Payables [Member]	Mar. 01, 2009 SLC Pipeline [Member]	Mar. 01, 2009 Finder's Fee [Member] SLC Pipeline [Member]
Business Acquisition [Line Items]
Equity Method Investment, Aggregate Cost																$ 28,000,000	$ 2,500,000
Notes Issued															150,000,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares													3,807,615	3,807,615
Throughput Agreements, Period										15 years
Business Acquisition, Annual Revenue Commitments													47,000,000
Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment													88,100,000
Business Acquisition, Purchase Price Allocation, Goodwill Amount													207,400,000
Other Significant Noncash Transaction, Value of Consideration Given													295,500,000
Promissory notes issued to related party at acquisition closing													150,000,000
Revenues	68,324,000	49,268,000	[1]	50,940,000	45,017,000	49,369,000	46,549,000	45,483,000	40,696,000	213,549,000	182,097,000	146,561,000		7,100,000
Net Income (Loss) Attributable to Parent	29,701,000	14,114,000	[1]	19,013,000	15,169,000	18,473,000	16,259,000	13,435,000	10,702,000	77,997,000	58,869,000	66,014,000		1,600,000
Operating Costs and Expenses										62,202,000	52,947,000	44,003,000		3,800,000
Noncash Capital Contribution, Operating Costs														2,300,000
Business Acquisition, Pro Forma Information
Revenues										253,679,000	229,113,000
Net income										$ 109,087,000	$ 90,828,000
Basic and diluted earnings per unit										$ 3.46	$ 2.94

[1] As a result of our November 9, 2011 tankage and terminal asset acquisition from HFC (see Note 3), we have retrospectively adjusted our third quarter of 2011 operating costs and expenses to include expenses incurred by HFC prior to our acquisition. Therefore, summarized quarterly financial data for the third quarter of the year ended December 31, 2011 does not agree to amounts previously reported.