v2.4.1.9
Marketable Securities (Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity) (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 28, 2015
Dec. 27, 2014
Cost    
Due in one year or less $ 269,931us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost  
Due after one year through five years 960,640us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost  
Due after five years through ten years 213,954us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost  
Due after ten years 91,932us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost  
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total 1,536,457us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis  
Estimated Fair Value    
Due in one year or less 270,212us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue  
Due after one year through five years 958,255us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue  
Due after five years through ten years 210,294us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue  
Due after ten years 90,553us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue  
Estimated Fair Value (Net Carrying Amount) $ 1,529,314us-gaap_AvailableForSaleSecurities $ 1,575,333us-gaap_AvailableForSaleSecurities [1]
[1] Certain available-for-sale securities held as of December 27, 2014 have been reclassified among major security types to conform to the current year presentation. These reclassifications had no effect on fair value measurement.