XML 56 R34.htm IDEA: XBRL DOCUMENT v3.8.0.1
INVENTORIES (Tables)
 3 Months Ended
Mar. 31, 2018
Inventory Disclosure [Abstract]  
Schedule of Inventory
Inventory components consist of the following:
 
March 31,
2018
 
December 31,
2017
Coal
$
17,104

 
$
11,411

Supplies
43,662

 
42,009

Total Inventories
$
60,766

 
$
53,420