Investments and Fair Value Measurements-Fixed Income Maturities (Details 7) (Fixed Income Securities [Member], USD $) In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013
Fixed Income Securities [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Due in one year or less	$ 860,203
After one year through five years	2,603,444
After five years through ten years	122,637
After ten years	647,111
Total, Amortized Cost	4,233,395	5,128,833
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Due in one year or less	861,915
After one year through five years	2,606,289
After five years through ten years	122,643
After ten years	647,914
Total, Fair Value	$ 4,238,761	$ 5,145,253