Inventories (Tables)

9 Months Ended

Sep. 30, 2021

Inventory Disclosure [Abstract]

Inventories

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

Inventories (Allowance)

	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