Condensed Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Oct. 02, 2011	Sep. 26, 2010	Oct. 02, 2011	Sep. 26, 2010
Condensed Consolidated Statements of Income [Abstract]
Net revenues	$ 150,180	$ 146,529	$ 301,802	$ 289,138
Cost of revenues	51,096	50,411	101,955	100,112
Gross profit	99,084	96,118	199,847	189,026
Operating expenses:
Engineering and development	37,871	32,792	75,563	67,501
Sales and marketing	20,442	20,420	41,705	40,850
General and administrative	8,854	8,031	18,017	16,499
Special charges				931
Total operating expenses	67,167	61,243	135,285	125,781
Operating income	31,917	34,875	64,562	63,245
Interest and other income, net	1,080	1,809	2,128	3,485
Income before income taxes	32,997	36,684	66,690	66,730
Income taxes	4,343	6,698	5,610	11,295
Net income	$ 28,654	$ 29,986	$ 61,080	$ 55,435
Net income per share:
Basic	$ 0.28	$ 0.28	$ 0.59	$ 0.50
Diluted	$ 0.28	$ 0.28	$ 0.58	$ 0.50
Number of shares used in per share calculations:
Basic	103,273	108,220	103,976	109,823
Diluted	103,562	109,039	104,676	111,385