XML 50 R35.htm IDEA: XBRL DOCUMENT v3.20.2
Note 8 - Inventories (Tables)
6 Months Ended
Jun. 30, 2020
Notes Tables  
Schedule of Inventory, Current [Table Text Block]
   

June 30,

   

December 31,

 
   

2020

   

2019

 

Coal

  $ 6,970     $ 2,484  

Supplies

    54,071       51,647  

Total Inventories

  $ 61,041     $ 54,131