XML 66 R57.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
SIGNIFICANT ACCOUNTING POLICIES - Change in Retirement Obligations (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]        
Beginning Balance $ 2,030 $ 1,714    
Additions 0 456    
Settlements (20) (204)    
Revision of estimate 0 4    
Accretions 64 60    
Ending Balance 2,074 2,030    
Asset retirement obligations - short term     $ 380 $ 342
Asset retirement obligations - long term     1,694 1,688
Total asset retirement obligations $ 2,030 $ 2,030 $ 2,074 $ 2,030