Inventories (Tables)

9 Months Ended

Sep. 30, 2013

Inventory Disclosure [Abstract]

Inventories

	September 30, 2013			December 31, 2012
	(in thousands)
Raw materials	$	27,096		$	28,155
Work in process	3,691			2,757
Finished goods	3,400			2,065
	34,187			32,977
Less:  Allowance for excess and obsolete inventories	(804		)	(363		)
Total, net	$	33,383		$	32,614

Inventories (Allowance)

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

	Three months ended				Nine months ended
	September 30, 2013		September 30, 2012		September 30, 2013			September 30, 2012
Allowance for excess and obsolete inventories:	(in thousands)
Balance, beginning of period	$	537	$	300	$	363		$	300
Provisions for excess and obsolete inventories	267		—		468			—
Inventories written off	—		—		(27		)	—
Balance, end of period	$	804	$	300	$	804		$	300