Marketable Securities (Maturities of Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 29, 2013	Dec. 29, 2012
Marketable Securities [Abstract]
Amortized Cost, Due within one year	$ 7,158
Fair Value, Due within one year	6,848
Amortized Cost, Due after one year through five years	41,983
Fair Value, Due after one year through five years	41,447
Amortized Cost, Due after five years through ten years	16,936
Fair Value, Due after five years through ten years	16,940
Amortized Cost, Due after ten years	1,501
Fair Value, Due after ten years	1,501
Amortized Cost, Equity securities	1,074
Fair Value, Equity securities	8,541
Available-for-sale Securities, Amortized Cost Basis, Total	68,652	73,976
Available-for-sale Securities, Fair Value, Total	$ 75,277	$ 82,501