CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
NET REVENUES		$ 104,688	$ 88,036
COST OF REVENUES		54,212	43,548
GROSS PROFIT		50,476	44,488
OPERATING EXPENSES:
Research and development		16,640	14,779
Sales and marketing		12,216	11,406
General and administrative		8,704	7,850
Total operating expenses		37,560	34,035
INCOME FROM OPERATIONS		12,916	10,453
OTHER INCOME		506	261
INCOME BEFORE INCOME TAXES		13,422	10,714
PROVISION FOR (BENEFIT FROM) INCOME TAXES		(677)	335
NET INCOME		$ 14,099	$ 10,379
EARNINGS PER SHARE:
Basic (in dollars per share)		$ 0.48	$ 0.36
Diluted (in dollars per share)	[1]	$ 0.47	$ 0.35
SHARES USED IN PER SHARE CALCULATION:
Basic (in shares)		29,456	28,679
Diluted (in shares)		30,248	29,244

[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 2017 and 2016 calculations as the shares were not contingently issuable as of the end of the reporting periods.