Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements of Income [Abstract]
Sales	$ 134,735	$ 165,522
Cost of sales	60,648	66,727
Gross Profit	74,087	98,795
Selling, general and administrative expenses	33,111	29,552
Research and development expenses	24,795	23,637
Operating Income	16,181	45,606
Interest and dividend income	1,861	1,789
Interest expense	(588)	(602)
Net realized investment gain	2,467	2,767
Other income (expense), net	141	(125)
Income before provision for income taxes	20,062	49,435
Provision for income taxes	(7,102)	(15,177)
Net Income	$ 12,960	$ 34,258
Weighted average shares outstanding - basic	63,809	64,189
Weighted average shares outstanding - diluted	64,849	65,957
Earnings per common share - basic	$ 0.20	$ 0.53
Earnings per common share - diluted	$ 0.20	$ 0.52
Dividend per share	$ 0.09	$ 0.09