Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net sales:
Product	$ 273,807	$ 288,224	$ 535,381	$ 550,488
Software maintenance	27,984	24,487	55,923	46,897
Total net sales	301,791	312,711	591,304	597,385
Cost of sales:
Product	75,621	80,642	150,502	150,263
Software maintenance	1,054	1,179	2,509	2,760
Total cost of sales	76,675	81,821	153,011	153,023
Gross profit	225,116	230,890	438,293	444,362
Operating expenses:
Sales and marketing	111,855	119,374	221,408	231,290
Research and development	55,409	55,851	115,929	111,110
General and administrative	23,165	23,640	46,136	46,113
Total operating expenses	190,429	198,865	383,473	388,513
Operating income	34,687	32,025	54,820	55,849
Other income:
Interest income	341	234	694	431
Net foreign exchange (loss) gain	(577)	(603)	(2,251)	(553)
Other (loss) income, net	25	265	653	353
Income before income taxes	34,476	31,921	53,916	56,080
(Benefit from) provision for income taxes	9,534	7,398	13,970	12,834
Net income	$ 24,942	$ 24,523	$ 39,946	$ 43,246
Basic earnings per share	$ 0.19	$ 0.19	$ 0.31	$ 0.34
Weighted average shares outstanding - basic	128,682	126,887	128,363	126,433
Diluted earnings per share	$ 0.19	$ 0.19	$ 0.31	$ 0.34
Weighted average shares outstanding - diluted	129,337	127,512	129,013	127,123
Dividends declared per share	$ 0.19	$ 0.15	$ 0.38	$ 0.30