v2.4.0.6
Working Interest Acquisitions - Allocation of Total Purchase Price of Working Interest Acquisition (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2012
38% Working Interest Acquisition [Member]
Dec. 31, 2012
10% Working Interest Acquisition [Member]
Purchase price:        
Acquisition price     $ 76,000 $ 21,500
Asset retirement obligations assumed     547 132
Post-closing purchase price adjustments     (5,720) (453)
Total 70,827 21,179 70,827 21,179
Allocation:        
Wells, equipment and related facilities     51,447 15,613
Mineral interests in oil and gas properties     19,380 5,566
Total     $ 70,827 $ 21,179