v2.4.0.8
Marketable Securities (Available for Sale Securities Measured at Estimated Fair Value on Recurring Basis) (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 28, 2013
Dec. 29, 2012
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total $ 1,651,968 $ 1,641,395
Fair Value, Measurements, Recurring
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 1,651,968 1,641,395
Fair Value, Measurements, Recurring | Mortgage-Backed Securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 437,330 650,895
Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 647,354 499,857
Fair Value, Measurements, Recurring | Corporate Bond Securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 457,148 399,941
Fair Value, Measurements, Recurring | Common Stock
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 29,854 22,982
Fair Value, Measurements, Recurring | Other securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 80,282 67,720
Fair Value, Measurements, Recurring | Level 1
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 29,854 22,982
Fair Value, Measurements, Recurring | Level 1 | Mortgage-Backed Securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 1 | Obligations of states and political subdivisions
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 1 | Corporate Bond Securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 1 | Common Stock
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 29,854 22,982
Fair Value, Measurements, Recurring | Level 1 | Other securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 2
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 1,622,114 1,618,413
Fair Value, Measurements, Recurring | Level 2 | Mortgage-Backed Securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 437,330 650,895
Fair Value, Measurements, Recurring | Level 2 | Obligations of states and political subdivisions
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 647,354 499,857
Fair Value, Measurements, Recurring | Level 2 | Corporate Bond Securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 457,148 399,941
Fair Value, Measurements, Recurring | Level 2 | Common Stock
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 2 | Other securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 80,282 67,720
Fair Value, Measurements, Recurring | Level 3
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 3 | Mortgage-Backed Securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 3 | Obligations of states and political subdivisions
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 3 | Corporate Bond Securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 3 | Common Stock
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total 0 0
Fair Value, Measurements, Recurring | Level 3 | Other securities
   
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Total $ 0 $ 0