Convertible Debentures and Revolving Credit Facility (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011	Mar. 31, 2012		Jun. 30, 2010
Debt Instrument [Line Items]
Amortization of debt discount			$ 7,897	$ 7,732
Carrying value of embedded derivative component	1,545		1,545		931
Convertible Debt, Noncurrent	915,109		915,109		906,569	[1]
2.625% Senior Convertible Debentures [Member]
Debt Instrument [Line Items]
Principal amount of Debentures	600,000		600,000		600,000		600,000
Contractual coupon interest	3,938	3,938	7,875	7,875
Amortization of debt issuance costs	362	362	724	724
Amortization of debt discount	2,763	2,763	5,526	5,526
Total interest expense related to the debentures	7,063	7,063	14,125	14,125
Debt Instrument, Unamortized Discount	(72,539)		(72,539)		(80,311)
Convertible Debt, Noncurrent	548,423		548,423		542,897
Debt Instrument, Convertible, Carrying Amount of Equity Component	105,620		105,620		105,620
3.125% Junior Convertible Debentures [Member]
Debt Instrument [Line Items]
Principal amount of Debentures	689,635		689,635		689,635
Contractual coupon interest	5,388	5,388	10,776	10,776
Amortization of debt issuance costs	55	55	112	112
Amortization of embedded derivative	14	14	29	29
Amortization of debt discount	1,196	1,113	2,371	2,206
Fair value adjustment of embedded derivative	0	1,434	614	1,062
Total interest expense related to the debentures	6,653	8,004	13,902	14,185
Debt Instrument, Unamortized Discount	(323,077)		(323,077)		(325,448)
Debt Instrument Unamortized Discount Of Embedded Derivative From Date Of Issuance	(1,417)		(1,417)		(1,446)
Debt Instrument Carrying Amount Of Liability Component	365,141		365,141		362,741
Carrying value of embedded derivative component	1,545		1,545		931
Convertible Debt, Noncurrent	366,686		366,686		363,672
Debt Instrument, Convertible, Carrying Amount of Equity Component	$ 229,513		$ 229,513		$ 229,513

[1] Derived from audited financial statements