XML 65 R44.htm IDEA: XBRL DOCUMENT v3.8.0.1
Note 14 - Asset Retirement Obligation (Tables)
 12 Months Ended
Dec. 31, 2017
Notes Tables  
Schedule of Asset Retirement Obligations [Table Text Block]
   
Year Ended December 31,
  
   
2017
   
2016
 
   
(Dollars in thousands)
  
Balance at beginning of year
   $
23,348
     $
20,856
  
Revision in estimated cash flows
    
1,888
      
303
  
Liabilities incurred
    
—
      
540
  
Accretion expense
    
1,874
      
1,649
  
Balance at end of year
   $
27,110
     $
23,348