Commitment and Contingencies (Tables)

6 Months Ended

Jun. 30, 2017

Commitments and Contingencies Disclosure [Abstract]

Schedule of Product Warranty Liability

The following table provides the changes in our product warranties, which are included in accrued liabilities:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2017			2016			2017			2016
	(in thousands)
Warranty, beginning of period	$	589		$	687		$	639		$	580
Warranty costs accrued	54			207			114			477
Settlements of warranty claims	(114		)	(177		)	(224		)	(340		)
Warranty, end of period	$	529		$	717		$	529		$	717