Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Product	$ 360,344	$ 307,189	$ 247,654
Services and other revenues	80,556	73,396	66,373
Total revenues	440,900	380,585	314,027
Cost of revenues:
Cost of product revenues	173,419	144,997	112,369
Cost of services and other revenues	33,621	32,189	31,070
Total cost of revenues	207,040	177,186	143,439
Gross profit	233,860	203,399	170,588
Operating expenses:
Research and development	27,802	29,105	23,726
Selling, general and administrative	156,475	138,995	119,736
Total operating expenses	184,277	168,100	143,462
Income from operations	49,583	35,299	27,126
Interest and other (expense), net	(1,079)	(270)	(51)
Income before provision for income taxes	48,504	35,029	27,075
Provision for income taxes	17,986	11,050	10,897
Net income	$ 30,518	$ 23,979	$ 16,178
Net income per share:
Basic (in dollars per share)	$ 0.86	$ 0.69	$ 0.49
Diluted (in dollars per share)	$ 0.83	$ 0.67	$ 0.47
Weighted-average shares:
Basic (in shares)	35,650	34,736	33,307
Diluted (in shares)	36,622	35,777	34,213