Inventories

9 Months Ended

Sep. 30, 2020

Inventory Disclosure [Abstract]

Inventories

Inventories

Inventories are valued at the lower of cost or net realizable value. Cost is determined by the first-in, first-out (“FIFO”) method. We establish an allowance for excess and obsolete inventories based on product line changes, the feasibility of substituting parts and the need for supply and replacement parts.

The components of inventories and related changes in the allowance for excess and obsolete inventories account are as follows:

	September 30, 2020		December 31, 2019
	(in thousands)
Raw materials	$	76,673	$	68,842
Work in process	1,541		1,825
Finished goods	4,717		5,578
Total, gross	82,931		76,245
Less:  Allowance for excess and obsolete inventories	(4,112)		(2,644)
Total, net	$	78,819	$	73,601

	Three Months Ended				Nine Months Ended
	September 30, 2020		September 30, 2019		September 30, 2020		September 30, 2019
Allowance for excess and obsolete inventories:	(in thousands)
Balance, beginning of period	$	2,373	$	2,350	$	2,644	$	1,210
Provisions (recoveries) for excess and	1,969		(150)		1,776		1,003
obsolete inventories
Inventories written off	(230)		—		(308)		(13)
Balance, end of period	$	4,112	$	2,200	$	4,112	$	2,200