Marketable Securities (Details 1) (USD $) In Thousands, unless otherwise specified	Jan. 01, 2012
Schedule of Amortized Cost and Estimated Fair Value of Debt Securities
Due in one year or less, Amortized Cost	$ 108,574
Due after one year through three years, Amortized Cost	147,688
Due after three years through five years, Amortized Cost	20,977
Due after five years, Amortized Cost	43,606
Total amortized cost of debt securities	320,845
Due in one year or less, Estimated Fair Value	108,884
Due after one year through three years, Estimated Fair Value	147,830
Due after three years through five years, Estimated Fair Value	20,972
Due after five years, Estimated Fair Value	43,749
Total estimated fair value of debt securities	$ 321,435

Available for sale securities debt maturities after five years amortized cost.

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