v2.4.0.6
Marketable Securities (Classified as Available-For-Sale Securities) (Details) (USD $)
In Thousands, unless otherwise specified
 9 Months Ended 12 Months Ended
Sep. 28, 2013
Dec. 29, 2012
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 1,762,859 $ 1,632,233
Gross Unrealized Gains 15,003 17,320
Gross Unrealized Losses (48,191) (6,884)
Other Than Temporary Impairment (1,274) (1,274)
Estimated Fair Value (Net Carrying Amount) 1,728,397 1,641,395
Mortgage-Backed Securities [Member]
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 534,722 644,388
Gross Unrealized Gains 4,386 8,894
Gross Unrealized Losses (20,268) (2,387)
Other Than Temporary Impairment 0 0
Estimated Fair Value (Net Carrying Amount) 518,840 650,895
Obligations of States and Political Subdivisions [Member]
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 711,989 499,241
Gross Unrealized Gains 1,649 2,345
Gross Unrealized Losses (23,023) (1,729)
Other Than Temporary Impairment 0 0
Estimated Fair Value (Net Carrying Amount) 690,615 499,857
U.S. Corporate Bonds [Member]
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 424,439 400,310
Gross Unrealized Gains 1,658 3,138
Gross Unrealized Losses (4,478) (2,233)
Other Than Temporary Impairment (1,274) (1,274)
Estimated Fair Value (Net Carrying Amount) 420,345 399,941
Common Stock [Member]
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 23,795 21,113
Gross Unrealized Gains 3,975 2,392
Gross Unrealized Losses (335) (523)
Other Than Temporary Impairment 0 0
Estimated Fair Value (Net Carrying Amount) 27,435 22,982
Other [Member]
    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 67,914 67,181
Gross Unrealized Gains 3,335 551
Gross Unrealized Losses (87) (12)
Other Than Temporary Impairment 0 0
Estimated Fair Value (Net Carrying Amount) $ 71,162 $ 67,720