Product Warranty (Tables)

9 Months Ended

Sep. 30, 2018

Product Warranty

Schedule of product warranty liability

	Nine months ended
	September 30,
	2018		2017
	(in thousands)
Balance at January 1 (beginning of year)	$	4,502	$	2,666
Warranties issued during the period		4,294		3,898
Settlements made during the period		(4,566)		(1,614)
Changes in estimate of liability for pre-existing warranties during the period		650		(562)
Balance at September 30 (end of period)	$	4,880	$	4,388
Amount classified as current	$	4,545	$	4,154
Amount classified as long-term		335		234
Total warranty liability	$	4,880	$	4,388