v2.4.0.8
Marketable Securities (Available for Sale Securities Measured at Estimated Fair Value on Recurring Basis) (Details) (USD $)
In Thousands, unless otherwise specified
Jun. 28, 2014
Dec. 28, 2013
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total $ 1,617,004 $ 1,651,968
Mortgage-Backed Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 380,211 437,330
Obligations of States and Political Subdivisions [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 600,823 647,354
Corporate Bond Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 517,867 457,148
Common Stocks [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 30,850 29,854
Other securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 87,253 80,282
Level 1 [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 30,850 29,854
Level 1 [Member] | Mortgage-Backed Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 1 [Member] | Obligations of States and Political Subdivisions [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 1 [Member] | Corporate Bond Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 1 [Member] | Common Stocks [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 30,850 29,854
Level 1 [Member] | Other securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 2 [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 1,586,154 1,622,114
Level 2 [Member] | Mortgage-Backed Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 380,211 437,330
Level 2 [Member] | Obligations of States and Political Subdivisions [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 600,823 647,354
Level 2 [Member] | Corporate Bond Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 517,867 457,148
Level 2 [Member] | Common Stocks [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 2 [Member] | Other securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 87,253 80,282
Level 3 [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 3 [Member] | Mortgage-Backed Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 3 [Member] | Obligations of States and Political Subdivisions [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 3 [Member] | Corporate Bond Securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 3 [Member] | Common Stocks [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Level 3 [Member] | Other securities [Member]
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total $ 0 $ 0