The following summarizes our inventory, recorded at the lower of weighted average cost or estimated net realizable value, as of September 30, 2017, and December 31, 2016 (in thousands):



	September 30, 2017		December 31, 2016
Finished goods product inventory	$	47,088	$	52,571
In-process mineral inventory	24,700		22,126
Total product inventory	71,788		74,697
Current parts inventory, net	12,014		19,658
Total current inventory, net	83,802		94,355
Long-term parts inventory, net	28,890		21,037
Total inventory, net	$	112,692	$	115,392