Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Net sales:
Product	$ 239,335	$ 218,610
Software maintenance	21,798	19,240
Total net sales	261,133	237,850
Cost of sales:
Product	59,791	50,958
Software maintenance	1,557	1,518
Total cost of sales	61,348	52,476
Gross profit	199,785	185,374
Operating expenses:
Sales and marketing	100,052	87,155
Research and development	54,015	42,868
General and administrative	21,374	18,839
Total operating expenses	175,441	148,862
Operating income	24,344	36,512
Other income:
Interest income	230	341
Net foreign exchange (loss)	(888)	(223)
Other income, net	104	446
Income before income taxes	23,790	37,076
Provision for income taxes	5,148	6,615
Net income	$ 18,642	$ 30,461
Basic earnings per share	$ 0.15	$ 0.26
Weighted average shares outstanding - basic	120,908	118,693
Diluted earnings per share	$ 0.15	$ 0.25
Weighted average shares outstanding - diluted	121,972	120,443
Dividends declared per share	$ 0.14	$ 0.10