Marketable Securities (Schedule of Cost and Estimated Fair Value of Available-for-sale Securities by Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 27, 2014	Mar. 29, 2014
Marketable Securities [Abstract]
Within 1 year, Amortized Cost	$ 106,136	$ 263,418
After 1 year, Amortized Cost	3,418	89,422
Within 1 year, Estimated Fair Value	106,061	263,417
After 1 year, Estimated Fair Value	3,404	89,243
Amortized Cost	109,554	352,840
Estimated Fair Value	$ 109,465	$ 352,660