Inventories

9 Months Ended

Sep. 30, 2021

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, 2021		December 31, 2020
	(in thousands)
Raw materials	$	97,167	$	76,238
Work in process	4,749		2,088
Finished goods	4,929		7,154
Total, gross	106,845		85,480
Less:  Allowance for excess and obsolete inventories	(2,292)		(3,261)
Total, net	$	104,553	$	82,219

	Three Months Ended				Nine Months Ended
	September 30, 2021		September 30, 2020		September 30, 2021		September 30, 2020
Allowance for excess and obsolete inventories:	(in thousands)
Balance, beginning of period	$	2,726	$	2,373	$	3,261	$	2,644
Provisions for excess and obsolete	86		1,969		378		1,776
inventories
Inventories written off	(520)		(230)		(1,347)		(308)
Balance, end of period	$	2,292	$	4,112	$	2,292	$	4,112