CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
NET REVENUES	$ 298,739		$ 299,803		$ 215,701
COST OF REVENUES	158,093		147,262		107,633
GROSS PROFIT	140,646		152,541		108,068
OPERATING EXPENSES:
Research and development	40,295		35,886		30,473
Sales and marketing	32,624		31,167		25,018
General and administrative	24,508		25,562		23,967
Total operating expenses	97,427		92,615		79,458
INCOME FROM OPERATIONS	43,219		59,926		28,610
OTHER INCOME (EXPENSE)
Interest income	2,054		2,096		2,175
Interest expense	0		(3)		(3)
Other, net	(178)		(214)		(259)
Total other income	1,876		1,879		1,913
INCOME BEFORE PROVISION FOR INCOME TAXES	45,095		61,805		30,523
PROVISION FOR INCOME TAXES	10,804		12,341		7,254
NET INCOME	$ 34,291		$ 49,464		$ 23,269
EARNINGS PER SHARE:
Basic (per share)	$ 1.2		$ 1.78		$ 0.86
Diluted (per share)	$ 1.14	[1]	$ 1.67	[1]	$ 0.82	[1]
SHARES USED IN PER SHARE CALCULATION:
Basic (in shares)	28,609		27,837		26,920
Diluted (in shares)	29,964	[1]	29,556	[1]	28,297	[1]

[1] The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share when they become contingently issuable per ASC 260-10, Earnings per Share and excludes such shares when they are not contingently issuable. The Company has excluded all performance-based awards underlying the 2011 awards in the 2011 calculation as those shares were not contingently issuable as of the end of the period, and has included all performance-based awards underlying the 2010 and 2009 awards in the 2010 and 2009 calculation, respectively, as those shares were contingently issuable upon the satisfaction of the annual targets consisting of net revenue and non-GAAP operating earnings as of the end of the period.