Supplemental Guarantor / Non-Guarantor Financial Information Condensed Consolidated Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 2,830	$ 6,352	$ 5,237	$ 6,369
Accounts receivable	40,129	34,736
Accounts Receivable, Related Parties, Current	0	0
Prepaid and other current assets	4,383	3,874
Total current assets	47,342	44,962
Properties and equipment, net	980,479	957,814
Investments in subsidiaries	0	0
Transportation agreements, net	80,703	87,650
Goodwill	256,498	256,498
Investment in SLC Pipeline	24,478	24,741
Other assets	12,055	10,843
Total assets	1,401,555	1,382,508
Current liabilities:
Accounts payable	17,881	22,898
Accounts Payable, Related Parties, Current	0	0
Accrued interest	6,615	10,239
Deferred revenue	12,432	13,981
Accrued property taxes	2,703	2,603
Other current liabilities	4,571	1,845
Total current liabilities	44,202	51,566
Long-term debt	867,579	807,630
Other long-term liabilities	18,145	14,585
Deferred Revenue	29,392	21,669
Class B unit	26,793	20,124
Equity - partners	320,362	369,446
Equity - noncontrolling interest	95,082	97,488
Total liabilities and equity	1,401,555	1,382,508
Parent [Member]
Current assets:
Cash and cash equivalents	2	2	2	2
Accounts receivable	0	0
Accounts Receivable, Related Parties, Current	0	0
Prepaid and other current assets	212	234
Total current assets	214	236
Properties and equipment, net	0	0
Investments in subsidiaries	622,100	885,598
Transportation agreements, net	0	0
Goodwill	0	0
Investment in SLC Pipeline	0	0
Other assets	1,319	1,684
Total assets	623,633	887,518
Current liabilities:
Accounts payable	0	0
Accounts Payable, Related Parties, Current	0	62,516
Accrued interest	6,500	10,198
Deferred revenue	0	0
Accrued property taxes	0	0
Other current liabilities	45	629
Total current liabilities	6,545	73,343
Long-term debt	296,579	444,630
Other long-term liabilities	147	99
Deferred Revenue	0	0
Class B unit	0	0
Equity - partners	320,362	369,446
Equity - noncontrolling interest	0	0
Total liabilities and equity	623,633	887,518
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	2,828	1,447	823	3,267
Accounts receivable	34,274	31,107
Accounts Receivable, Related Parties, Current	0	62,516
Prepaid and other current assets	2,856	2,590
Total current assets	39,958	97,660
Properties and equipment, net	596,988	564,847
Investments in subsidiaries	285,247	292,464
Transportation agreements, net	80,703	87,650
Goodwill	256,498	256,498
Investment in SLC Pipeline	24,478	24,741
Other assets	10,736	9,159
Total assets	1,294,608	1,333,019
Current liabilities:
Accounts payable	15,495	18,966
Accounts Payable, Related Parties, Current	0	0
Accrued interest	115	41
Deferred revenue	5,672	6,406
Accrued property taxes	1,902	1,661
Other current liabilities	4,408	1,216
Total current liabilities	27,592	28,290
Long-term debt	571,000	363,000
Other long-term liabilities	17,731	14,338
Deferred Revenue	29,392	21,669
Class B unit	26,793	20,124
Equity - partners	622,100	885,598
Equity - noncontrolling interest	0	0
Total liabilities and equity	1,294,608	1,333,019
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	0	4,903	4,412	3,100
Accounts receivable	6,044	4,543
Accounts Receivable, Related Parties, Current	0	0
Prepaid and other current assets	1,315	1,050
Total current assets	7,359	10,496
Properties and equipment, net	383,491	392,967
Investments in subsidiaries	0	0
Transportation agreements, net	0	0
Goodwill	0	0
Investment in SLC Pipeline	0	0
Other assets	0	0
Total assets	390,850	403,463
Current liabilities:
Accounts payable	2,575	4,846
Accounts Payable, Related Parties, Current	0	0
Accrued interest	0	0
Deferred revenue	6,760	7,575
Accrued property taxes	801	942
Other current liabilities	118	0
Total current liabilities	10,254	13,363
Long-term debt	0	0
Other long-term liabilities	267	148
Deferred Revenue	0	0
Class B unit	0	0
Equity - partners	380,329	389,952
Equity - noncontrolling interest	0	0
Total liabilities and equity	390,850	403,463
Eliminations [Member]
Current assets:
Cash and cash equivalents	0	0	0	0
Accounts receivable	(189)	(914)
Accounts Receivable, Related Parties, Current	0	(62,516)
Prepaid and other current assets	0	0
Total current assets	(189)	(63,430)
Properties and equipment, net	0	0
Investments in subsidiaries	(907,347)	(1,178,062)
Transportation agreements, net	0	0
Goodwill	0	0
Investment in SLC Pipeline	0	0
Other assets	0	0
Total assets	(907,536)	(1,241,492)
Current liabilities:
Accounts payable	(189)	(914)
Accounts Payable, Related Parties, Current	0	(62,516)
Accrued interest	0	0
Deferred revenue	0	0
Accrued property taxes	0	0
Other current liabilities	0	0
Total current liabilities	(189)	(63,430)
Long-term debt	0	0
Other long-term liabilities	0	0
Deferred Revenue	0	0
Class B unit	0	0
Equity - partners	(1,002,429)	(1,275,550)
Equity - noncontrolling interest	95,082	97,488
Total liabilities and equity	$ (907,536)	$ (1,241,492)