CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Products	$ 71,045	$ 91,592
Services	28,128	27,636
Total revenues	99,173	119,228
Cost of sales:
Products	52,175	66,462
Services	15,575	15,978
Total cost of sales	67,750	82,440
Selling, general and administrative	28,253	25,808
Engineering and product development	9,447	11,850
Total costs and expenses	105,450	120,098
Operating loss	(6,277)	(870)
Interest income	1,797	937
Interest expense	(2)	(15)
Income before income taxes	(4,482)	52
Income tax provision (benefit)	2,901	(42)
Net income (loss)	$ (7,383)	$ 94
Earnings per common share:
Basic (in dollars per share)	$ (0.20)	$ 0.00
Diluted (in dollars per share)	$ (0.20)	$ 0.00
Weighted average common shares outstanding:
Basic (in shares)	37,729	37,525
Diluted (in shares)	37,729	37,693