Marketable Securities (Maturities of Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 29, 2012	Dec. 31, 2011
Marketable Securities [Abstract]
Amortized Cost, Due within one year	$ 4,078
Fair Value, Due within one year	3,933
Amortized Cost, Due after one year through five years	49,607
Fair Value, Due after one year through five years	49,255
Amortized Cost, Due after five years through ten years	17,655
Fair Value, Due after five years through ten years	18,963
Amortized Cost, Due after ten years	1,500
Fair Value, Due after ten years	1,500
Amortized Cost, Equity securities	1,136
Fair Value, Equity securities	8,850
Available-for-sale Securities, Amortized Cost Basis, Total	73,976	80,101
Available-for-sale Securities, Fair Value, Total	$ 82,501	$ 89,348