Marketable Securities (Schedule of Cost and Estimated Fair Value of Available-for-sale Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 26, 2015	Mar. 28, 2015
Marketable Securities [Abstract]
Within 1 year, Amortized Cost	$ 86,488	$ 124,275
After 1 year, Amortized Cost	22,517	60,116
Amortized Cost	109,005	184,391
Within 1 year, Estimated Fair Value	86,460	124,246
After 1 year, Estimated Fair Value	22,393	60,072
Estimated Fair Value	$ 108,853	$ 184,318