CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Revenues:
Product revenues	$ 46,218	$ 42,023	$ 88,793	$ 84,318
Services and other revenues	14,787	12,670	29,372	24,535
Total revenues	61,005	54,693	118,165	108,853
Cost of revenues:
Cost of product revenues	19,730	19,009	37,566	38,274
Cost of services and other revenues	7,468	6,816	15,142	14,125
Total cost of revenues	27,198	25,825	52,708	52,399
Gross profit	33,807	28,868	65,457	56,454
Operating expenses:
Research and development	5,280	4,950	10,120	9,515
Selling, general and administrative	24,297	20,426	50,078	41,938
Total operating expenses	29,577	25,376	60,198	51,453
Income from operations	4,230	3,492	5,259	5,001
Interest and other income, net of other expense	71	53	125	127
Income before provision for income taxes	4,301	3,545	5,384	5,128
Provision for income taxes	1,714	1,580	2,127	2,184
Net income	$ 2,587	$ 1,965	$ 3,257	$ 2,944
Net income per share-basic (in dollars per share)	$ 0.08	$ 0.06	$ 0.10	$ 0.09
Net income per share-diluted (in dollars per share)	$ 0.08	$ 0.06	$ 0.10	$ 0.09
Weighted average shares outstanding:
Basic (in shares)	33,003	32,567	33,093	32,388
Diluted (in shares)	33,981	33,452	34,039	33,303