CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Products	$ 102,092	$ 116,048	$ 193,684	$ 251,242
Services	25,830	26,391	53,466	57,758
Total revenues	127,922	142,439	247,150	309,000
Cost of sales:
Products	74,991	65,407	141,453	142,329
Services	12,558	14,474	28,536	30,648
Total cost of sales	87,549	79,881	169,989	172,977
Selling, general and administrative	31,179	5,762	56,987	18,983
Engineering and product development	10,308	11,579	22,158	22,480
Total costs and expenses	129,036	97,222	249,134	214,440
Operating income (loss)	(1,114)	45,217	(1,984)	94,560
Interest income	1,070	541	2,007	1,023
Interest expense	(18)	(10)	(33)	(14)
Income before income taxes	(62)	45,748	(10)	95,569
Income tax provision (benefit)	(77)	9,611	(120)	22,663
Net income	$ 15	$ 36,137	$ 110	$ 72,906
Earnings per common share:
Basic (in dollars per share)	$ 0.00	$ 0.96	$ 0.00	$ 1.94
Diluted (in dollars per share)	$ 0.00	$ 0.96	$ 0.00	$ 1.93
Weighted average common shares outstanding:
Basic (in shares)	37,528	37,564	37,526	37,658
Diluted (in shares)	37,718	37,713	37,706	37,779