Accrued Warranty (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Product Warranties Disclosures [Abstract]
Balance at beginning of year	$ 3,335	$ 3,044	$ 3,315
Provision charged to cost of revenue	1,673	2,025	1,684
Acquisition related warranty accrual	23	132	90
Use of provision	(1,849)	(1,454)	(2,003)
Divestiture of JK Lasers		(389)
Foreign currency exchange rate changes	(40)	(23)	(42)
Balance at end of year	$ 3,142	$ 3,335	$ 3,044