Marketable Securities (Schedule of Cost And Estimated Fair Value Of Available-for-sale Securities By Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 29, 2013	Mar. 30, 2013
Marketable Securities [Abstract]
Within 1 year, Amortized Cost	$ 165,625	$ 105,290
After 1 year, Amortized Cost	39,511	65,004
Within 1 year, Estimated Fair Value	165,540	105,235
After 1 year, Estimated Fair Value	39,408	64,910
Amortized Cost	205,136	170,294
Estimated Fair Value	$ 204,948	$ 170,145