Marketable Securities (Tables)

12 Months Ended

Mar. 31, 2012

Mar. 26, 2011

Marketable Securities [Abstract]

Schedule Of Available-for-sale Securities

As of March 31, 2012:	Amortized Cost	Gross Unrealized Gains	Gross Unrealized Losses	Estimated Fair Value (Net Carrying Amount)
Corporate securities – U.S.................................................	48,011	33	(19)	48,025
U.S. Treasury securities......................................................	30,264	1	(4)	30,261
Agency discount notes.......................................................	16,789	8	(1)	16,796
Commercial paper..............................................................	23,719	5	(15)	23,709
Total securities.................................................................	$118,783	$47	$(39)	$118,791

As of March 26, 2011:	Amortized Cost	Gross Unrealized Gains	Gross Unrealized Losses	Estimated Fair Value (Net Carrying Amount)
Corporate securities – U.S.................................................	64,228	22	(38)	64,212
U.S. Treasury securities......................................................	35,268	13	—	35,281
Agency discount notes.......................................................	16,588	5	(2)	16,591
Commercial paper..............................................................	56,130	23	(7)	56,146
Total securities.................................................................	$172,214	$63	$(47)	$172,230

Schedule of Cost And Estimated Fair Value Of Available-for-sale Securities By Contractual Maturity

	March 31, 2012		March 26, 2011
	Amortized Cost	Estimated Fair Value	Amortized Cost	Estimated Fair Value
Within 1 year.......................................................................	$115,871	$115,876	$159,516	$ 159,528
After 1 year.........................................................................	2,912	2,915	12,698	12,702
	$118,783	$118,791	$172,214	$172,230