Reportable Segments 3 (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Transportation And Storage [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	100.00%	100.00%	100.00%
Percent Of Revenues Company	29.00%	31.00%	34.00%
Gathering And Processing [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	100.00%	100.00%	100.00%
Percent Of Revenues Company	44.00%	42.00%	35.00%
BG LNG Services [Member] | Transportation And Storage [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	30.00%	29.00%	22.00%
Percent Of Revenues Company	9.00%	9.00%	8.00%
ProLiance [Member] | Transportation And Storage [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	13.00%	13.00%	13.00%
Percent Of Revenues Company	4.00%	4.00%	4.00%
Other Top 10 Customers [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	20.00%	24.00%	48.00%
Other Top 10 Customers [Member] | Transportation And Storage [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	21.00%	23.00%	26.00%
Percent Of Revenues Company	6.00%	7.00%	9.00%
Other Top 10 Customers [Member] | Gathering And Processing [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues Company	9.00%	10.00%	17.00%
Remaining Customers [Member] | Transportation And Storage [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	36.00%	35.00%	39.00%
Percent Of Revenues Company	10.00%	11.00%	13.00%
Remaining Customers [Member] | Gathering And Processing [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	6.00%	10.00%	33.00%
Percent Of Revenues Company	3.00%	5.00%	12.00%
ConocoPhilips Company [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	62.00%	54.00%	7.00%
ConocoPhilips Company [Member] | Gathering And Processing [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues Company	27.00%	22.00%	2.00%
Lone Star NGL Product Services, LLC [Member] | Gathering And Processing [Member]
Revenue, Major Customer [Line Items]
Percent Of Revenues	12.00%	12.00%	12.00%
Percent Of Revenues Company	5.00%	5.00%	4.00%