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Accounts Receivable-Related Parties (Narrative) (Details) (USD $) |  |  | 0 Months Ended | 3 Months Ended | 9 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2013 | Dec. 31, 2012 | Jul. 02, 2008 Everest Operations Management LLC [Member] | Sep. 30, 2012 Everest Operations Management LLC [Member] | Sep. 30, 2012 Everest Operations Management LLC [Member] | Jul. 01, 2008 Everest Operations Management LLC [Member]
Related Party Transaction [Line Items] |  |  |  |  |  |
Accounts receivable-related parties | $ 29,797,000 | $ 34,848,000 |  |  |  |
Percentage of proportionate share of acquisition or divestiture consideration payable to affiliates |  |  |  |  |  | 1.00%
Required notice period, counterparty |  |  | 30 days |  |  |
Reimbursement for general and administrative expenses performed for related party under acquisition team agreement |  |  |  | $ 400,000 | $ 900,000 |

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