Product Warranties (Tables)

6 Months Ended

Jun. 30, 2018

Guarantees and Product Warranties [Abstract]

Product Warranty Activity

Product warranty activity for the three and six months ended June 30 was as follows (in thousands):

	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Balance at the beginning of the period	$	346		$	185		$	290		$	214
Accruals for warranties for products sold in the period		10			91			133			195
Fulfillment of warranty obligations		(20	)		(24	)		(77	)		(97	)
Revisions of estimated obligations		(10	)		(8	)		(20	)		(68	)
Balance at the end of the period	$	326		$	244		$	326		$	244