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ASSET RETIREMENT OBLIGATIONS AND RESTRICTED CASH - Schedule of Change in Asset Retirement Obligation (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2016
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2016
Dec. 31, 2015
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]            
Asset retirement obligation, beginning of period   $ 8,573 $ 5,683      
Revision of estimate   4,186 877 $ 9    
Acquired in asset acquisitions or business combinations   5,454 2,145      
Accretion of liabilities $ 906 906 494 412    
Settlements   (2,086) (626)      
Asset retirement obligation, end of period 17,033 17,033 8,573 5,683    
Asset Retirement Obligation [Abstract]            
Current         $ 32 $ 1,000
Non-current         17,001 7,573
Asset retirement obligation, end of period $ 17,033 $ 8,573 $ 5,683 $ 5,683 $ 17,033 $ 8,573