Financial Instruments (Details 2) (USD $)	Dec. 27, 2014
Investments, All Other Investments [Abstract]
Marketable debt securities with contractual maturities greater than one year but classified as short-term investment	$ 1,082,400,000
Amortized cost and estimated fair value of marketable debt securities
Amortized Cost Due in one year or less	1,410,505,000
Amortized Cost Due after one year through five years	292,035,000
Amortized Cost Due after five years through ten years	383,473,000
Amortized Cost Due after ten years	959,961,000
Amortized Cost Total	3,045,974,000
Estimated Fair Value Due in one year or less	1,410,527,000
Estimated Fair Value Due after one year through five years	291,562,000
Estimated Fair Value Due after five years through ten years	383,800,000
Estimated Fair Value Due after ten years	965,354,000
Estimated Fair Value Total	$ 3,051,243,000