Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Revenues	$ 149,461	$ 119,100	$ 410,833	$ 364,933
Cost of revenues	62,968	46,203	166,442	143,666
Gross margin	86,493	72,897	244,391	221,267
Operating expenses:
Research and development	34,768	31,715	101,943	101,248
Selling, general and administrative	24,495	27,254	82,075	85,168
Operating expenses	59,263	58,969	184,018	186,416
Operating income	27,230	13,928	60,373	34,851
Other income (expense):
Interest income	243	388	1,103	1,432
Interest expense	(234)	(4)	(299)	(14)
Other income (expense), net	(161)	(81)	807	292
Income before income taxes	27,078	14,231	61,984	36,561
Provision for income taxes	17,054	2,976	17,131	13,894
Net income	$ 10,024	$ 11,255	$ 44,853	$ 22,667
Earnings per share:
Basic (in dollars per share)	$ 0.24	$ 0.26	$ 1.06	$ 0.52
Diluted (in dollars per share)	$ 0.24	$ 0.26	$ 1.04	$ 0.50
Weighted-average common shares outstanding:
Basic (in shares)	41,735	42,834	42,279	43,902
Diluted (in shares)	42,520	43,919	43,261	45,305