Long Term Debt (Details 3) (USD $)	6 Months Ended								6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011 Parent [Member]	Jun. 30, 2010 Parent [Member]	Jun. 30, 2011 Co-Issuer [Member]	Dec. 31, 2010 Co-Issuer [Member]	Jun. 30, 2010 Co-Issuer [Member]	Dec. 31, 2009 Co-Issuer [Member]	Jun. 30, 2011 Guarantor Subsidiaries [Member]	Jun. 30, 2010 Guarantor Subsidiaries [Member]	Jun. 30, 2011 Investment in Non-Guarantor Subsidiaries [Member]	Jun. 30, 2010 Investment in Non-Guarantor Subsidiaries [Member]	Jun. 30, 2011 Eliminations [Member]	Jun. 30, 2010 Eliminations [Member]
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities	$ 76,006,000	$ 65,414,000	$ (83,120,000)	$ (31,290,000)					$ 159,126,000	$ 96,704,000	$ 12,323,000	$ 10,993,000	$ (12,323,000)	$ (10,993,000)
Cash Flows From Investing Activities:
Additions to property, plant and equipment and intangibles	(102,429,000)	(60,368,000)							(102,429,000)	(60,368,000)
Acquisitions	(16,084,000)								(16,084,000)
Investments in unconsolidated affiliates	(65,027,000)	(1,538,000)							(65,027,000)	(1,538,000)	(65,027,000)	(1,538,000)	65,027,000	1,538,000
Distributions from unconsolidated affiliates	1,249,000	1,997,000							1,249,000	1,997,000	1,249,000	1,997,000	(1,249,000)	(1,997,000)
Investment in consolidated affiliates			(80,319,000)	(52,465,000)									80,319,000	52,465,000
Distributions from consolidated affiliates			56,703,000	95,355,000									(56,703,000)	(95,355,000)
Proceeds from sale of assets	141,000	266,000							141,000	266,000
Other	(179,000)	523,000							(179,000)	523,000
Net cash (used in) provided by investing activities	(182,329,000)	(59,120,000)	(23,616,000)	42,890,000					(182,329,000)	(59,120,000)	(63,778,000)	459,000	87,394,000	(43,349,000)
Cash Flows From Financing Activities:
Proceeds from long-term debt	605,000,000	80,000,000	605,000,000	80,000,000
Repayment of long-term debt	(392,665,000)	(170,000,000)	(392,665,000)	(170,000,000)
Deferred financing costs	(15,670,000)		(15,670,000)
Payments of premiums and expenses on redemption of unsecured debt	(14,572,000)		(14,572,000)
Distributions to unitholders	(76,571,000)	(69,430,000)	(76,571,000)	(69,430,000)
Proceeds from public offering of common units		164,786,000		164,786,000
Equity offering costs	(4,000)	(531,000)	(4,000)	(531,000)
Contributions from parent									80,319,000	52,465,000	65,027,000		(145,346,000)	(52,465,000)
Distributions to parent									(56,703,000)	(95,355,000)			56,703,000	95,355,000
Other	2,431,000	991,000	2,431,000	991,000								1,538,000		(1,538,000)
Net cash provided by financing activities	107,949,000	5,816,000	107,949,000	5,816,000					23,616,000	(42,890,000)	65,027,000	1,538,000	(88,643,000)	41,352,000
Net increase in cash and cash equivalents	1,626,000	12,110,000	1,213,000	17,416,000					413,000	(5,306,000)	13,572,000	12,990,000	(13,572,000)	(12,990,000)
Cash and cash equivalents, beginning of year	59,930,000	44,692,000	9,650,000	3,861,000	0	0	(1,000)	(1,000)	50,280,000	40,832,000	85,851,000	59,896,000	(85,851,000)	(59,896,000)
Cash and cash equivalents, end of period	$ 61,556,000	$ 56,802,000	$ 10,863,000	$ 21,277,000	$ 0	$ 0	$ (1,000)	$ (1,000)	$ 50,693,000	$ 35,526,000	$ 99,423,000	$ 72,886,000	$ (99,423,000)	$ (72,886,000)