XML 69 R49.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
ASSET RETIREMENT OBLIGATION - Summary of Asset Retirement Obligation (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
ASSET RETIREMENT OBLIGATION    
Balance, beginning of period $ 6,203 $ 5,731
Liabilities settled (293) (521)
Accretion expense 390 993
Balance, end of period 6,300 6,203
Less: Current portion (894) (708)
Non-current Portion $ 5,406 $ 5,495