Marketable Securities (Schedule of Available-for-sale Securities) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Sep. 28, 2013	Mar. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 239,611	$ 170,294
Gross Unrealized Gains	92	15
Gross Unrealized Losses	(26)	(164)
Estimated Fair Value (Net Carrying Amount)	239,677	170,145
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	152,099	94,798
Gross Unrealized Gains	55	2
Gross Unrealized Losses	(26)	(133)
Estimated Fair Value (Net Carrying Amount)	152,128	94,667
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	42,579	34,380
Gross Unrealized Gains	14	4
Gross Unrealized Losses	0	(3)
Estimated Fair Value (Net Carrying Amount)	42,593	34,381
Agency Discount Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,021	1,027
Gross Unrealized Gains	3	0
Gross Unrealized Losses	0	0
Estimated Fair Value (Net Carrying Amount)	4,024	1,027
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	40,912	40,089
Gross Unrealized Gains	20	9
Gross Unrealized Losses	0	(28)
Estimated Fair Value (Net Carrying Amount)	$ 40,932	$ 40,070