CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Products	$ 75,885	$ 101,277	$ 269,570	$ 352,519
Services	24,461	22,363	77,928	80,121
Total revenues	100,346	123,640	347,498	432,640
Cost of sales:
Products	48,761	63,879	190,214	206,208
Services	14,289	13,754	42,825	44,402
Total cost of sales	63,050	77,633	233,039	250,610
Selling, general and administrative	27,994	12,504	84,981	31,487
Engineering and product development	10,379	10,570	32,537	33,050
Impairment and other charges	60,968	0	60,968	0
Total costs and expenses	162,391	100,707	411,525	315,147
Total costs and expenses	(62,045)	22,933	(64,027)	117,493
Interest income	957	945	2,963	1,968
Interest expense	(12)	(1)	(44)	(15)
Income (loss) before income taxes	(61,100)	23,877	(61,108)	119,446
Income tax provision (benefit)	(31,840)	4,864	(31,959)	27,527
Net income (loss)	$ (29,260)	$ 19,013	$ (29,149)	$ 91,919
Earnings (loss) per common share:
Basic (in dollars per share)	$ (0.78)	$ 0.51	$ (0.78)	$ 2.45
Diluted (in dollars per share)	$ (0.78)	$ 0.51	$ (0.78)	$ 2.44
Weighted average common shares outstanding:
Basic (in shares)	37,528	37,371	37,527	37,562
Diluted (in shares)	37,528	37,554	37,527	37,699