XML 40 R29.htm IDEA: XBRL DOCUMENT v3.21.1
Asset Retirement Obligations (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Changes in the Company's asset retirement obligations      
Beginning asset retirement obligations $ 38,542    
Liabilities incurred during period 166    
Liabilities settled during period (79)    
Accretion expense 500 $ 476  
Ending asset retirement obligations 39,129    
Less: current asset retirement obligations [1] (409)    
Long-term asset retirement obligations $ 38,720   $ 37,919
[1] Included in accrued liabilities in the Company’s interim unaudited condensed consolidated balance sheet at March 31, 2021.