Reportable Segments 1 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended														6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2012 Successor [Member]	Jun. 30, 2012 Successor [Member]	Jun. 30, 2012 Successor [Member] Transportation and Storage [Member]	Jun. 30, 2012 Successor [Member] Transportation and Storage [Member]	Jun. 30, 2012 Successor [Member] Gathering and Processing [Member]	Jun. 30, 2012 Successor [Member] Gathering and Processing [Member]	Jun. 30, 2012 Successor [Member] Distribution [Member]	Jun. 30, 2012 Successor [Member] Distribution [Member]	Jun. 30, 2012 Successor [Member] Total segment [Member]	Jun. 30, 2012 Successor [Member] Total segment [Member]	Jun. 30, 2012 Successor [Member] Corporate and other activities [Member]	Jun. 30, 2012 Successor [Member] Corporate and other activities [Member]	Mar. 25, 2012 Predecessor [Member]	Jun. 30, 2011 Predecessor [Member]	Jun. 30, 2011 Predecessor [Member]	Dec. 31, 2011 Predecessor [Member]	Mar. 25, 2012 Predecessor [Member] Transportation and Storage [Member]	Jun. 30, 2011 Predecessor [Member] Transportation and Storage [Member]	Jun. 30, 2011 Predecessor [Member] Transportation and Storage [Member]	Dec. 31, 2011 Predecessor [Member] Transportation and Storage [Member]	Mar. 25, 2012 Predecessor [Member] Gathering and Processing [Member]	Jun. 30, 2011 Predecessor [Member] Gathering and Processing [Member]	Jun. 30, 2011 Predecessor [Member] Gathering and Processing [Member]	Dec. 31, 2011 Predecessor [Member] Gathering and Processing [Member]	Mar. 25, 2012 Predecessor [Member] Distribution [Member]	Jun. 30, 2011 Predecessor [Member] Distribution [Member]	Jun. 30, 2011 Predecessor [Member] Distribution [Member]	Dec. 31, 2011 Predecessor [Member] Distribution [Member]	Mar. 25, 2012 Predecessor [Member] Total segment [Member]	Jun. 30, 2011 Predecessor [Member] Total segment [Member]	Jun. 30, 2011 Predecessor [Member] Total segment [Member]	Dec. 31, 2011 Predecessor [Member] Total segment [Member]	Mar. 25, 2012 Predecessor [Member] Corporate and other activities [Member]	Jun. 30, 2011 Predecessor [Member] Corporate and other activities [Member]	Jun. 30, 2011 Predecessor [Member] Corporate and other activities [Member]	Dec. 31, 2011 Predecessor [Member] Corporate and other activities [Member]
Segment Reporting Information [Line Items]
Capital Expenditures		$ 84,207		$ 34,205		$ 34,930		$ 14,231		$ 83,366		$ 841	$ 71,772		$ 117,995		$ 21,047		$ 39,169		$ 42,698		$ 56,513		$ 7,075		$ 20,409		$ 70,820		$ 116,091		$ 952		$ 1,904
Operating revenues from external customers	472,470	512,182	185,216	198,692	197,476	216,833	86,220	94,505	468,912	510,030	3,558	2,152	633,649	631,607	1,378,429		193,921	189,760	392,054		246,463	328,515	552,167		190,499	109,076	425,649		630,883	627,351	1,369,870		2,766	4,256	8,559
Segment Adjusted EBITDA	162,232	105,543	115,919	82,644	22,362	10,859	23,314	13,446			637	(1,406)	225,753	253,824	475,815		185,706	203,368	370,120		25,338	39,473	60,206		33,554	12,027	44,304						(18,845)	(1,044)	1,185
Depreciation and amortization	(74,476)	(79,199)											(56,544)	(59,295)	(118,622)
Unrealized gains on unhedged derivative activities	0	0											0	331	(14,413)
Net gain on curtailment of OPEB plans		15,332											0		0
Non-cash equity-based compensation, accretion expense and amortization of regulatory assets	(4,860)	(4,860)											(1,350)	(2,700)	(4,654)
Other, net	175	191											284	224	366
Proportionate share of unconsolidated investments' interest, depreciation and allowance for equity funds used during construction	(3,185)	(3,181)											(44,948)	(52,090)	(63,323)
Interest expense	(57,303)	(61,684)											(50,407)	(54,933)	(110,504)
Earnings (loss) before income taxes	22,583	(27,858)											72,788	85,361	164,665
Income tax (benefit) expense	(10,858)	1,076											(22,871)	(25,588)	(44,230)
Net earnings (loss)	11,725	(26,782)											49,917	59,773	120,435
Total assets	9,897,448	9,897,448	5,755,369	5,755,369	2,805,884	2,805,884	1,245,794	1,245,794	9,807,047	9,807,047	90,401	90,401				8,270,859				5,288,967				1,742,516				1,075,253				8,106,736				164,123
Expenditures for long-lived assets	$ 82,678		$ 32,676		$ 34,930		$ 14,231		$ 81,837		$ 841			$ 64,582				$ 28,911				$ 20,903				$ 13,447				$ 63,261				$ 1,321