Long-Term Debt (Details 5) (USD $)	0 Months Ended		9 Months Ended
	Oct. 31, 2012	Jan. 31, 2012	Sep. 30, 2012	Sep. 30, 2011
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities			$ 123,780,000	$ 122,789,000
Cash Flows From Investing Activities:
Additions to property, plant and equipment and intangibles			(254,048,000)	(180,639,000)
Acquisitions				(16,084,000)
Investments in unconsolidated affiliates			(60,677,000)	(105,111,000)
Distributions from unconsolidated affiliates			3,279,000	2,368,000
Proceeds from sale of assets			23,850,000	248,000
Other			2,604,000	104,000
Net cash used in investing activities			(284,992,000)	(299,114,000)
Cash Flows From Financing Activities:
Proceeds from long-term debt			420,375,000	725,000,000
Repayment of long-term debt			(322,000,000)	(412,665,000)
Deferred financing costs			(3,539,000)	(15,743,000)
Payments of premiums and expenses on redemption of unsecured debt				(14,572,000)
Distributions to unitholders			(126,090,000)	(114,834,000)
Proceeds from public offering of common units	201,449,000	187,763,000	188,083,000
Equity offering costs			(379,000)	(4,000)
Other			1,284,000	2,747,000
Net cash provided by financing activities			157,734,000	169,929,000
Net increase (decrease) in cash and cash equivalents			(3,478,000)	(6,396,000)
Cash and cash equivalents, beginning of year			56,962,000	59,930,000
Cash and cash equivalents, end of period			53,484,000	53,534,000
Parent
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities			(138,954,000)	(124,348,000)
Cash Flows From Investing Activities:
Investment in consolidated affiliates			(58,437,000)	(99,864,000)
Distributions from consolidated affiliates			53,248,000	48,775,000
Net cash used in investing activities			(5,189,000)	(51,089,000)
Cash Flows From Financing Activities:
Proceeds from long-term debt			420,375,000	725,000,000
Repayment of long-term debt			(322,000,000)	(412,665,000)
Deferred financing costs			(3,539,000)	(15,743,000)
Payments of premiums and expenses on redemption of unsecured debt				(14,572,000)
Distributions to unitholders			(126,090,000)	(114,834,000)
Proceeds from public offering of common units			188,083,000
Equity offering costs			(379,000)	(4,000)
Other			1,284,000	2,747,000
Net cash provided by financing activities			157,734,000	169,929,000
Net increase (decrease) in cash and cash equivalents			13,591,000	(5,508,000)
Cash and cash equivalents, beginning of year			9,064,000	9,650,000
Cash and cash equivalents, end of period			22,655,000	4,142,000
Guarantor Subsidiaries
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities			262,734,000	247,137,000
Cash Flows From Investing Activities:
Additions to property, plant and equipment and intangibles			(254,048,000)	(180,639,000)
Acquisitions				(16,084,000)
Investments in unconsolidated affiliates			(60,677,000)	(105,111,000)
Distributions from unconsolidated affiliates			3,279,000	2,368,000
Proceeds from sale of assets			23,850,000	248,000
Other			2,604,000	104,000
Net cash used in investing activities			(284,992,000)	(299,114,000)
Cash Flows From Financing Activities:
Contributions from parent			58,437,000	99,864,000
Distributions to parent			(53,248,000)	(48,775,000)
Net cash provided by financing activities			5,189,000	51,089,000
Net increase (decrease) in cash and cash equivalents			(17,069,000)	(888,000)
Cash and cash equivalents, beginning of year			47,898,000	50,280,000
Cash and cash equivalents, end of period			30,829,000	49,392,000
Investment in Non-Guarantor Subsidiaries
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities			31,229,000	17,961,000
Cash Flows From Investing Activities:
Investments in unconsolidated affiliates			(60,677,000)	(105,111,000)
Distributions from unconsolidated affiliates			3,279,000	2,368,000
Net cash used in investing activities			(57,398,000)	(102,743,000)
Cash Flows From Financing Activities:
Other			60,677,000	105,111,000
Net cash provided by financing activities			60,677,000	105,111,000
Net increase (decrease) in cash and cash equivalents			34,508,000	20,329,000
Cash and cash equivalents, beginning of year			121,322,000	85,851,000
Cash and cash equivalents, end of period			155,830,000	106,180,000
Eliminations
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities			(31,229,000)	(17,961,000)
Cash Flows From Investing Activities:
Investments in unconsolidated affiliates			60,677,000	105,111,000
Distributions from unconsolidated affiliates			(3,279,000)	(2,368,000)
Investment in consolidated affiliates			58,437,000	99,864,000
Distributions from consolidated affiliates			(53,248,000)	(48,775,000)
Net cash used in investing activities			62,587,000	153,832,000
Cash Flows From Financing Activities:
Contributions from parent			(58,437,000)	(99,864,000)
Distributions to parent			(53,248,000)	48,775,000
Other			(60,677,000)	(105,111,000)
Net cash provided by financing activities			(65,866,000)	(156,200,000)
Net increase (decrease) in cash and cash equivalents			(34,508,000)	(20,329,000)
Cash and cash equivalents, beginning of year			(121,322,000)	(85,851,000)
Cash and cash equivalents, end of period			$ (155,830,000)	$ (106,180,000)