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Inventories
12 Months Ended
Dec. 31, 2018
Inventory Disclosure [Abstract]  
Inventories
INVENTORIES:

Inventory components consist of the following:
 
December 31,
 
2018
 
2017
Coal
$
4,642

 
$
11,411

Supplies
44,004

 
42,009

Total Inventories
$
48,646

 
$
53,420