Marketable Securities (Maturities of Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2013	Dec. 29, 2012
Marketable Securities [Abstract]
Amortized Cost, Due within one year	$ 5,431
Fair Value, Due within one year	5,140
Amortized Cost, Due after one year through five years	43,044
Fair Value, Due after one year through five years	42,529
Amortized Cost, Due after five years through ten years	16,720
Fair Value, Due after five years through ten years	16,654
Amortized Cost, Due after ten years	1,502
Fair Value, Due after ten years	1,502
Amortized Cost, Equity securities	970
Fair Value, Equity securities	7,864
Available-for-sale Securities, Amortized Cost Basis, Total	67,667	73,976
Available-for-sale Securities, Fair Value, Total	$ 73,689	$ 82,501