Annual report pursuant to Section 13 and 15(d)

Accounts Receivable-Related Parties (Narrative) (Details)

v2.4.0.6
Accounts Receivable-Related Parties (Narrative) (Details) (USD $)
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Mar. 01, 2008
Wexford [Member]
Dec. 31, 2011
Charles E. Davidson [Member]
Sep. 28, 2012
Charles E. Davidson [Member]
Maximum [Member]
Dec. 31, 2011
Orange Leaf Holdings, LLC [Member]
Other Income (Expense) [Member]
Dec. 31, 2010
Orange Leaf Holdings, LLC [Member]
Other Income (Expense) [Member]
Dec. 31, 2012
Everest Operations Management LLC [Member]
Dec. 31, 2011
Everest Operations Management LLC [Member]
Dec. 31, 2010
Everest Operations Management LLC [Member]
Jul. 01, 2008
Everest Operations Management LLC [Member]
Apr. 01, 2010
Windsor Niobrara LLC [Member]
Related Party Transaction [Line Items]                        
Accounts receivable-related parties $ 34,848,000 $ 4,731,000                    
Required notice term     60 days                  
Required notice period, counterparty     30 days               30 days  
Breach of contract, cure period     30 days                  
Ownership Of Company By Third Party       13.30% 1.00%              
Affiliates participation percentage in acquisition of leases                       50.00%
Rental income           66,000 20,000          
Percentage of proportionate share of acquisition or divestiture consideration payable to affiliates                     1.00%  
Reimbursement for general and administrative expenses performed for related party under acquisition team agreement               $ 1,087,000 $ 1,184,000 $ 0