Convertible Debentures and Revolving Credit Facility (Details) (USD $) In Thousands, unless otherwise specified	Dec. 29, 2012	Mar. 31, 2012
Debt Instrument [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability	$ 1,324	$ 931
Net carrying value of Debentures	918,883	906,569	[1]
2.625% Senior Convertible Debentures [Member]
Debt Instrument [Line Items]
Principal amount of Debentures	600,000	600,000
Unamortized discount of liability component	(68,653)	(80,311)
Hedge accounting adjustment - sale of interest rate swap	19,839	23,208
Net carrying value of Debentures	551,186	542,897
Equity component - net carrying value	105,620	105,620
3.125% Junior Convertible Debentures [Member]
Debt Instrument [Line Items]
Principal amount of Debentures	689,635	689,635
Unamortized discount of liability component	(321,860)	(325,448)
Unamortized discount of embedded derivative from date of issuance	(1,402)	(1,446)
Debt Instrument Carrying Amount Of Liability Component	366,373	362,741
Embedded Derivative, Fair Value of Embedded Derivative Liability	1,324	931
Net carrying value of Debentures	367,697	363,672
Equity component - net carrying value	$ 229,513	$ 229,513

[1] Derived from audited financial statements