Supplemental Guarantor / Non-Guarantor Financial Information Condensed Consolidated Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2008
Condensed Financial Statements, Captions [Line Items]
Sale of Stock, Percentage of Ownership before Transaction	70.00%
Current assets:
Cash and cash equivalents	$ 2,508	$ 3,269	$ 403	$ 5,269
Accounts receivable		34,071	22,508
Intercompany accounts receivable (payable)		0	0
Prepaid and other current assets		2,644	775
Total current assets		39,984	23,686
Properties and equipment, net		536,425	434,950
Investments in subsidiaries		0	0
Transportation agreements, net		101,543	108,489
Goodwill		256,498	49,109
Investment in SLC Pipeline		25,302	25,437
Other assets		7,204	1,602
Total assets		966,956	643,273
Current liabilities:
Accounts payable		11,406	10,238
Accrued interest		8,280	7,517
Deferred revenue		4,032	10,437
Accrued property taxes		2,196	1,990
Other current liabilities		1,777	1,262
Total current liabilities		27,691	31,444
Long-term debt		605,888	491,648
Other long-term liabilities		4,000	10,809
Partners' equity	193,864	329,377	109,372	8,120
Total liabilities and partners’ equity		966,956	643,273
Parent [Member]
Current assets:
Cash and cash equivalents	2	2	2	2
Accounts receivable		0	0
Intercompany accounts receivable (payable)		17,745	(92,230)
Prepaid and other current assets		266	235
Total current assets		18,013	(91,993)
Properties and equipment, net		0	0
Investments in subsidiaries		651,217	541,262
Transportation agreements, net		0	0
Goodwill		0	0
Investment in SLC Pipeline		0	0
Other assets		1,322	1,261
Total assets		670,552	450,530
Current liabilities:
Accounts payable		0	0
Accrued interest		7,498	7,498
Deferred revenue		0	0
Accrued property taxes		0	0
Other current liabilities		689	1,011
Total current liabilities		8,187	8,509
Long-term debt		332,988	332,649
Other long-term liabilities		0	0
Partners' equity		329,377	109,372
Total liabilities and partners’ equity		670,552	450,530
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	2,506	3,267	401	3,706
Accounts receivable		34,071	22,508
Intercompany accounts receivable (payable)		(17,745)	92,230
Prepaid and other current assets		2,378	540
Total current assets		21,971	115,679
Properties and equipment, net		536,425	434,950
Investments in subsidiaries		0	0
Transportation agreements, net		101,543	108,489
Goodwill		256,498	49,109
Investment in SLC Pipeline		25,302	25,437
Other assets		5,882	341
Total assets		947,621	734,005
Current liabilities:
Accounts payable		11,406	10,238
Accrued interest		782	19
Deferred revenue		4,032	10,437
Accrued property taxes		2,196	1,990
Other current liabilities		1,088	251
Total current liabilities		19,504	22,935
Long-term debt		272,900	158,999
Other long-term liabilities		4,000	10,809
Partners' equity		651,217	541,262
Total liabilities and partners’ equity		947,621	734,005
Eliminations [Member]
Current assets:
Cash and cash equivalents	0	0	0	0
Accounts receivable		0	0
Intercompany accounts receivable (payable)		0	0
Prepaid and other current assets		0	0
Total current assets		0	0
Properties and equipment, net		0	0
Investments in subsidiaries		(651,217)	(541,262)
Transportation agreements, net		0	0
Goodwill		0	0
Investment in SLC Pipeline		0	0
Other assets		0	0
Total assets		(651,217)	(541,262)
Current liabilities:
Accounts payable		0	0
Accrued interest		0	0
Deferred revenue		0	0
Accrued property taxes		0	0
Other current liabilities		0	0
Total current liabilities		0	0
Long-term debt		0	0
Other long-term liabilities		0	0
Partners' equity		(651,217)	(541,262)
Total liabilities and partners’ equity		$ (651,217)	$ (541,262)