Inventories, net (Tables)

3 Months Ended

Mar. 31, 2021

Inventory Disclosure [Abstract]

Schedule of Inventory

Inventories, net consisted of the following: 

	March 31, 2021		December 31, 2020
Raw coal	$	20,573	$	15,084
Saleable coal	62,688		69,262
Materials, supplies and other, net	25,610		23,705
Total inventories, net	$	108,871	$	108,051