Concentration Risk (Schedule Of Revenues And Cost Of Sales By Major Customer And Supplier) (Details) (USD $) In Thousands, unless otherwise specified	5 Months Ended	7 Months Ended	12 Months Ended
	May 25, 2010	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2009
Gathering And Processing [Member] | Successor [Member] | Customer A [Member]
Concentration Risk [Line Items]
Major customer, revenue amount		$ 131,724	$ 366,259
Gathering And Processing [Member] | Successor [Member] | Customer B [Member]
Concentration Risk [Line Items]
Major customer, revenue amount			0
Gathering And Processing [Member] | Successor [Member] | Supplier B [Member]
Concentration Risk [Line Items]
Major supplier, cost of sales amount	0	0	132,679	0
Gathering And Processing [Member] | Predecessor [Member] | Customer A [Member]
Concentration Risk [Line Items]
Major customer, revenue amount	88,003			123,524
Gathering And Processing [Member] | Predecessor [Member] | Customer B [Member]
Concentration Risk [Line Items]
Major customer, revenue amount	52,372
Gathering And Processing [Member] | Predecessor [Member] | Supplier A [Member]
Concentration Risk [Line Items]
Major supplier, cost of sales amount				143,435
Transportation [Member] | Successor [Member] | Supplier A [Member]
Concentration Risk [Line Items]
Major supplier, cost of sales amount		0	0
Transportation [Member] | Predecessor [Member] | Supplier A [Member]
Concentration Risk [Line Items]
Major supplier, cost of sales amount	$ 0			$ 14,053