Inventories

6 Months Ended

Jun. 30, 2019

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 are as follows:

	June 30, 2019			December 31, 2018
	(in thousands)
Raw materials	$	71,348		$	67,995
Work in process	3,133			4,060
Finished goods	4,913			6,767
	79,394			78,822
Less:  Allowance for excess and obsolete inventories	(2,350		)	(1,210		)
Total, net	$	77,044		$	77,612

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

	Three months ended						Six months ended
	June 30, 2019			June 30, 2018			June 30, 2019			June 30, 2018
Allowance for excess and obsolete inventories:	(in thousands)
Balance, beginning of period	$	1,567		$	1,209		$	1,210		$	1,118
Provisions for excess and obsolete inventories	796			217			1,153			318
Inventories written off	(13		)	(19		)	(13		)	(29		)
Balance, end of period	$	2,350		$	1,407		$	2,350		$	1,407