Inventories (Tables)

3 Months Ended

Mar. 31, 2016

Inventory Disclosure [Abstract]

Inventories

	March 31, 2016			December 31, 2015
	(in thousands)
Raw materials	$	36,152		$	33,853
Work in process	3,741			2,522
Finished goods	3,480			2,881
	43,373			39,256
Less:  Allowance for excess and obsolete inventories	(894		)	(757		)
Total, net	$	42,479		$	38,499

Inventories (Allowance)

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

	Three months ended
	March 31, 2016		March 31, 2015
Allowance for excess and obsolete inventories:	(in thousands)
Balance, beginning of period	$	757	$	714
Provisions for excess and obsolete inventories	137		41
Inventories written off	—		—
Balance, end of period	$	894	$	755