Fair Value Measurements (Details 1) (USD $)	3 Months Ended				9 Months Ended
	Dec. 29, 2012		Dec. 31, 2011		Dec. 29, 2012		Dec. 31, 2011
Changes in Level 3 instruments measured at fair value on a recurring basis
Balance as of beginning of period	$ 27,524,000		$ 27,041,000		$ 27,998,000		$ 34,005,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	221,000		655,000		(393,000)		(407,000)
Included in other comprehensive income	(318,000)		(747,000)		172,000		(1,299,000)
Sales and settlements, net	(350,000)	[1]	(300,000)	[1]	(700,000)	[1]	(5,650,000)	[1]
Balance as of end of period	$ 27,077,000		$ 26,649,000		$ 27,077,000		$ 26,649,000

[1] During the three months ended December 29, 2012 and December 31, 2011, $350 thousand and $300 thousand of student loan auction rate securities, respectively, were redeemed for cash at par value. During the first nine months ended December 29, 2012 and December 31, 2011, $700 thousand and $5.7 million of student loan auction rate securities, respectively, were redeemed for cash at par value.