Inventories (Tables)

3 Months Ended

Mar. 31, 2014

Inventory Disclosure [Abstract]

Inventories

	March 31, 2014			December 31, 2013
	(in thousands)
Raw materials	$	32,085		$	28,592
Work in process	2,474			2,286
Finished goods	915			1,841
	35,474			32,719
Less:  Allowance for excess and obsolete inventories	(583		)	(579		)
Total, net	$	34,891		$	32,140

Inventories (Allowance)

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

	Three months ended
	March 31, 2014		March 31, 2013
Allowance for excess and obsolete inventories:	(in thousands)
Balance, beginning of period	$	579	$	363
Provisions for excess and obsolete inventories	4		196
Inventories written off	—		(27		)
Balance, end of period	$	583	$	532