Condensed Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues:
Products	$ 149,706	$ 120,184
Services	27,418	17,483
Total revenues	177,124	137,667
Cost and expenses:
Products	92,123	66,921
Services	14,927	13,192
Total cost of sales	107,050	80,113
Selling, general and administrative	20,432	18,261
Engineering and product development	9,610	8,698
Total cost and expenses	137,092	107,072
Operating income	40,032	30,595
Interest income	103	99
Interest expense	(5)	(11)
Income before income taxes	40,130	30,683
Income tax provision	11,333	9,011
Net income	$ 28,797	$ 21,672
Earnings per common share:
Basic	$ 0.72	$ 0.54
Diluted	$ 0.71	$ 0.54
Weighted average common shares outstanding:
Basic	40,184	40,049
Diluted	40,411	40,320