Debt and Credit Facility (Details) (USD $)	3 Months Ended				3 Months Ended					3 Months Ended
	Jun. 28, 2014	Mar. 29, 2014		Mar. 29, 2014 Two And Six Two Five Percent Senior Convertible Debentures [Member]	Jun. 29, 2013 Two And One Two Five Percent 2019 Senior Debentures [Member]	Jun. 28, 2014 Three Point Zero Percent 2021 Senior Debentures [Member]	Mar. 29, 2014 Three Point Zero Percent 2021 Senior Debentures [Member]	Jun. 28, 2014 Two And One Two Five Percent 2019 Senior Debentures [Member]	Mar. 29, 2014 Two And One Two Five Percent 2019 Senior Debentures [Member]	Jun. 28, 2014 Two And Six Two Five Percent Senior Convertible Debentures [Member]	Mar. 29, 2014 Two And Six Two Five Percent Senior Convertible Debentures [Member]
Debt Instrument [Line Items]
Price Per Share To Be Purchase By Company Under Call Option										$ 29.64
Debt Instrument, Face Amount						$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 500,000,000	$ 600,000,000	$ 600,000,000
Debt Instrument, Unamortized Discount						(3,441,000)	(3,556,000)	(2,449,000)	(2,574,000)	(45,337,000)	(49,223,000)
Debt Instrument Carrying Amount Of Liability Component				565,001,000						567,764,000
2019 Debt instrument, Maturity Date	Mar. 15, 2019
2021 Debt instrument, Maturity Date	Mar. 15, 2021
Equity component - net carrying value										66,415,000	66,415,000
Discount Percent of Par						99.281%		99.477%
Proceeds from Issuance of Long-term Debt					990,100,000
Long-term Debt, Excluding Current Maturities	$ 994,110,000	$ 993,870,000	[1]

[1] Derived from audited financial statements