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ASSET RETIREMENT OBLIGATION (Details) (USD $)
3 Months Ended
Mar. 31, 2015
ASSET RETIREMENT OBLIGATION  
Fair market value of cash held in escrow that is legally restricted for potential plugging and abandonment liability $ 2,800,000us-gaap_AssetRetirementObligationLegallyRestrictedAssetsFairValue
Reconciliation of asset retirement obligations  
Balance at beginning of period 29,771,000us-gaap_AssetRetirementObligation
Liabilities incurred in current period 9,000us-gaap_AssetRetirementObligationLiabilitiesIncurred
Liabilities settled in current period (288,000)us-gaap_AssetRetirementObligationLiabilitiesSettled
Accretion expense 698,000us-gaap_AssetRetirementObligationAccretionExpense
Balance at end of period $ 30,190,000us-gaap_AssetRetirementObligation