Consolidated Statements of Income (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Sales
Total Sales	$ 529,277	$ 666,900	$ 636,781
Cost of Sales
Total Cost of Sales	325,712	363,265	345,451
Gross Profit	203,565	303,635	291,330
Selling, general and administrative expenses	124,440	135,583	131,848
Research and development expenses	124,547	130,666	124,909
Operating Income (Loss)	(45,422)	37,386	34,573
Interest and dividend income	4,026	4,380	3,918
Interest expense	(533)	(556)	(572)
Net investment gain (loss)	(4,050)	4,685	5,923
Other income (expense), net	1,286	(1,208)	(489)
Gain on bargain purchase of a business	11,322		3,542
Income (Loss) before (Provision) Benefit for Income Taxes	(33,371)	44,687	46,895
(Provision) benefit for income taxes	14,029	(20,847)	(11,666)
Net Income (Loss)	$ (19,342)	$ 23,840	$ 35,229
Weighted average shares outstanding – basic	47,880	48,153	48,724
Weighted average shares outstanding – diluted	47,880	48,699	48,949
Earnings (loss) per common share – basic	$ (0.40)	$ 0.50	$ 0.72
Earnings (loss) per common share – diluted	$ (0.40)	$ 0.49	$ 0.72
Product [Member]
Sales
Total Sales	$ 458,232	$ 540,396	$ 525,502
Cost of Sales
Total Cost of Sales	278,929	279,563	270,705
Service [Member]
Sales
Total Sales	71,045	126,504	111,279
Cost of Sales
Total Cost of Sales	$ 46,783	$ 83,702	$ 74,746