CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
NET REVENUES		$ 103,790	$ 88,878	$ 286,285	$ 256,700
COST OF REVENUES		52,597	44,717	144,508	126,229
GROSS PROFIT		51,193	44,161	141,777	130,471
OPERATING EXPENSES:
Research and development		15,906	13,888	46,544	43,693
Sales and marketing		12,029	11,129	35,453	35,701
General and administrative		8,789	7,361	24,772	23,133
Total operating expenses		36,724	32,378	106,769	102,527
INCOME FROM OPERATIONS		14,469	11,783	35,008	27,944
OTHER INCOME		282	428	779	219
INCOME BEFORE INCOME TAXES		14,751	12,211	35,787	28,163
PROVISION FOR INCOME TAXES		586	698	1,514	1,717
NET INCOME		$ 14,165	$ 11,513	$ 34,273	$ 26,446
EARNINGS PER SHARE:
Basic (in dollars per share)		$ 0.49	$ 0.40	$ 1.19	$ 0.91
Diluted (in dollars per share)	[1]	$ 0.48	$ 0.39	$ 1.16	$ 0.89
SHARES USED IN PER SHARE CALCULATION:
Basic (in shares)		28,972	28,855	28,834	29,175
Diluted (in shares)		29,625	29,298	29,480	29,856

[1] The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has excluded the shares underlying the outstanding performance-based awards in the 2016 and 2015 calculations as the shares were not contingently issuable as of the end of the reporting periods.