Investments and Fair Value Measurements-Fixed Income Maturities (Details 7) (Fixed Income Securities [Member], USD $) In Thousands, unless otherwise specified	Sep. 28, 2014	Dec. 29, 2013
Fixed Income Securities [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized Cost, due in one year or less	$ 777,581
Amortized Cost, due in years two through five	2,692,208
Amortized Cost, due in years six through ten	121,207
Amortized Cost, due after year ten	626,020
Amortized Cost	4,217,016	5,128,833
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Fair Value, due in one year or less	779,489
Fair Value, due in years two through five	2,702,665
Fair Value, due in years six through ten	121,216
Fair Value, due after year ten	627,651
Fair Value	$ 4,231,021	$ 5,145,253