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UNAUDITED SUPPLEMENTAL OIL AND GAS INFORMATION (Details 3) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward]      
Standardized measure, beginning of year $ 17,768 $ 81,889 $ 104,853
Sales of oil and gas, net of production costs (3,102) (2,944) (21,741)
Net changes in prices and production costs (9,248) (96,586) (17,376)
Changes in estimated future development costs 6,590 51,998 (1,869)
Extensions and discoveries 167 2,260 14,706
Sale of minerals in place (78) (13,339)
Revisions in previous quantity estimates (6,791) (27,693) (4,815)
Previously estimated development costs incurred   7,175
Net changes in income taxes   3,306 6,924
Accretion of discount 1,777 8,189 10,090
Changes in timing and other (336) (2,651) (2,719)
Standardized measure, end of year $ 6,747 $ 17,768 $ 81,889