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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
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2016
Mar. 31, 2017
Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]          
Asset retirement obligation, beginning of period $ 17,033 $ 8,573 $ 8,573    
Revision of estimate 0   4,186    
Acquired in asset acquisitions or business combinations 0   5,454    
Accretion of liabilities 345 175 906    
Settlements (97)   (2,086)    
Asset retirement obligation, end of period 17,281   17,033    
Asset Retirement Obligation [Abstract]          
Current       $ 32 $ 32
Non-current       17,249 17,001
Asset retirement obligation, end of period $ 17,033 $ 8,573 $ 8,573 $ 17,281 $ 17,033