Reportable Segments 1 (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended	3 Months Ended			0 Months Ended	3 Months Ended			0 Months Ended	3 Months Ended			0 Months Ended	3 Months Ended			0 Months Ended	3 Months Ended			0 Months Ended	3 Months Ended
	Mar. 31, 2012 Successor [Member]	Mar. 25, 2012 Predecessor [Member]	Mar. 31, 2011 Predecessor [Member]	Dec. 31, 2011 Predecessor [Member]	Mar. 31, 2012 Transportation And Storage [Member] Successor [Member]	Mar. 25, 2012 Transportation And Storage [Member] Predecessor [Member]	Mar. 31, 2011 Transportation And Storage [Member] Predecessor [Member]	Dec. 31, 2011 Transportation And Storage [Member] Predecessor [Member]	Mar. 31, 2012 Gathering And Processing [Member] Successor [Member]	Mar. 25, 2012 Gathering And Processing [Member] Predecessor [Member]	Mar. 31, 2011 Gathering And Processing [Member] Predecessor [Member]	Dec. 31, 2011 Gathering And Processing [Member] Predecessor [Member]	Mar. 31, 2012 Distribution [Member] Successor [Member]	Mar. 25, 2012 Distribution [Member] Predecessor [Member]	Mar. 31, 2011 Distribution [Member] Predecessor [Member]	Dec. 31, 2011 Distribution [Member] Predecessor [Member]	Mar. 31, 2012 Total Segment [Member] Successor [Member]	Mar. 25, 2012 Total Segment [Member] Predecessor [Member]	Mar. 31, 2011 Total Segment [Member] Predecessor [Member]	Dec. 31, 2011 Total Segment [Member] Predecessor [Member]	Mar. 31, 2012 Corporate And Other Activities [Member] Successor [Member]	Mar. 25, 2012 Corporate And Other Activities [Member] Predecessor [Member]	Mar. 31, 2011 Corporate And Other Activities [Member] Predecessor [Member]	Dec. 31, 2011 Corporate And Other Activities [Member] Predecessor [Member]
Segment Reporting Information [Line Items]
Operating revenues from external customers	$ 39,712	$ 633,649	$ 746,822		$ 13,476	$ 193,921	$ 202,294		$ 19,357	$ 246,463	$ 223,652		$ 8,285	$ 190,499	$ 316,573		$ 41,118	$ 630,883	$ 742,519		$ (1,406)	$ 2,766	$ 4,303
Depreciation and amortization	4,723	56,544	59,327		2,697	30,225	32,274		1,412	17,542	17,787		548	7,978	8,407		4,657	55,745	58,468		66	799	859
Earnings from unconsolidated investments	12	16,160	26,701		8	16,186	26,031		(10)	(195)	188										14	169	482
Adjusted EBITDA	(56,689)	225,753	221,991		(33,276)	185,706	166,752		(11,503)	25,338	20,733		(9,868)	33,554	32,277						(2,042)	(18,845)	2,229
Depreciation and amortization	(4,723)	(56,544)	(59,327)		(2,697)	(30,225)	(32,274)		(1,412)	(17,542)	(17,787)		(548)	(7,978)	(8,407)		(4,657)	(55,745)	(58,468)		(66)	(799)	(859)
Unrealized gains (losses) on unhedged derivative activities	0	0	(14,744)
Net gain on curtailment of OPEB plans	15,332	0	0
Non-cash equity-based compensation	0	(1,350)	(1,954)
Other, net	16	284	142
Proportionate share of unconsolidated investments' interest, depreciation and allowance for equity funds used during construction	4	(44,948)	(11,233)
Interest expense	(4,381)	(50,407)	(55,571)
Federal and state income tax expense (benefit)	11,934	(22,871)	(18,642)
Net earnings (loss)	(38,507)	49,917	60,662
Assets	10,044,024			8,270,859	5,890,054			5,288,967	2,730,322			1,742,516	1,260,397			1,075,253	9,880,773			8,106,736	163,251			164,123
Expenditures for long-lived assets	$ 1,529	$ 71,772	$ 53,413		$ 1,529	$ 21,047	$ 10,258		$ 0	$ 42,698	$ 35,610		$ 0	$ 7,075	$ 6,962		$ 1,529	$ 70,820	$ 52,830		$ 0	$ 952	$ 583