Condensed Consolidated Statements of Income (Unaudited) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Income Statement [Abstract]
NET REVENUES	$ 57,955,000		$ 59,857,000
COST OF REVENUES	28,606,000	[1]	28,638,000	[1]
GROSS PROFIT	29,349,000		31,219,000
OPERATING EXPENSES:
Research and development	13,964,000	[1]	15,481,000	[1]
Selling, general and administrative	11,375,000	[1]	12,436,000	[1]
Total operating expenses	25,339,000		27,917,000
INCOME FROM OPERATIONS	4,010,000		3,302,000
INTEREST AND OTHER INCOME (EXPENSE) :
Interest income	83,000		103,000
Other expense, net	(71,000)		(72,000)
Total interest and other income, net	12,000		31,000
INCOME BEFORE PROVISION FOR INCOME TAXES	4,022,000		3,333,000
PROVISION FOR INCOME TAXES	1,300,000		1,044,000
NET INCOME	$ 2,722,000		$ 2,289,000
NET INCOME PER SHARE:
Basic (Per Share)	$ 0.05		$ 0.04
Diluted (Per Share)	$ 0.05		$ 0.04
WEIGHTED AVERAGE SHARES USED IN COMPUTING PER SHARE AMOUNTS:
Basic (Shares)	56,617		56,388
Diluted (Shares)	58,282		57,208
CASH DIVIDENDS DECLARED PER COMMON SHARE	$ 0.05		$ 0.05

[1] Share-based compensation expense included in:Cost of revenues$274 $234Research and development861 690Selling, general and administrative982 798