Fair Value Of Financial Instruments (Schedule Of Fair Value Of Financial Assets) (Details) (Available-For-Sale Securities [Member], USD $) In Thousands	Sep. 24, 2011	Mar. 26, 2011
Fair value of financial assets	$ 145,933	$ 205,429
Corporate Debt Securities [Member]
Fair value of financial assets	55,450	64,212
Corporate Debt Securities [Member] | Significant Other Observable Inputs Level 2 [Member]
Fair value of financial assets	55,450	64,212
Money-Market Funds [Member]
Fair value of financial assets	16,545	17,700
Money-Market Funds [Member] | Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Fair value of financial assets	16,545	17,700
U.S. Treasury Securities [Member]
Fair value of financial assets	22,072	45,781
U.S. Treasury Securities [Member] | Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Fair value of financial assets	22,072	45,781
Agency Discount Notes [Member]
Fair value of financial assets	16,391	16,591
Agency Discount Notes [Member] | Significant Other Observable Inputs Level 2 [Member]
Fair value of financial assets	16,391	16,591
Commercial Paper [Member]
Fair value of financial assets	35,475	61,145
Commercial Paper [Member] | Significant Other Observable Inputs Level 2 [Member]
Fair value of financial assets	35,475	61,145
Quoted Prices In Active Markets For Identical Assets Level 1 [Member]
Fair value of financial assets	38,617	63,481
Significant Other Observable Inputs Level 2 [Member]
Fair value of financial assets	$ 107,316	$ 141,948