Acquisitions (Summary Of Fair Value Of Assets Acquired And Liabilities Assumed For October 2011 Purchase Agreement) (Details) (October 2011 Purchase Agreement [Member], USD $)	Oct. 03, 2011
October 2011 Purchase Agreement [Member]
Business Acquisition [Line Items]
Oil and gas properties, net	$ 441,207,000
Gas processing equipment net	251,000
Derivative instrument asset, net	64,671,000
Deferred tax asset	205,000
Long-term debt	(227,000,000)
Asset retirement obligation	(26,294,000)
Natural gas imbalance	(3,709,000)
Book value of net assets	249,331,000
Purchase price adjustment	2,715,000	[1]
Net assets (liabilities) acquired	$ 252,046,000

[1] The net assets contributed to us include the historical book value of the Predecessor as prescribed by our accounting policy for transactions between entities under common control in Note 2 - Summary of Significant Accounting Policies and a $2.7 million purchase price adjustment for natural gas imbalances in accordance with the purchase and sale agreement.