Temporarily Impaired Available for Sale Securities by Time Period Impaired (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 30, 2013	Dec. 29, 2012
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	$ 622,624	$ 858,549
Less Than 12 Months, Unrealized Losses	6,804	11,879
12 Months or Longer, Fair Value	9,117	14,260
12 Months or Longer, Unrealized Losses	3,189	3,621
Total, Fair Value	631,741	872,809
Total, Unrealized Losses	9,993	15,500
Tax exempt bonds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	323,493	566,914
Less Than 12 Months, Unrealized Losses	2,328	2,646
12 Months or Longer, Fair Value	0	0
12 Months or Longer, Unrealized Losses	0	0
Total, Fair Value	323,493	566,914
Total, Unrealized Losses	2,328	2,646
Taxable bonds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	243,368	81,876
Less Than 12 Months, Unrealized Losses	561	355
12 Months or Longer, Fair Value	0	0
12 Months or Longer, Unrealized Losses	0	0
Total, Fair Value	243,368	81,876
Total, Unrealized Losses	561	355
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	55,763	209,759
Less Than 12 Months, Unrealized Losses	3,915	8,878
12 Months or Longer, Fair Value	9,117	14,260
12 Months or Longer, Unrealized Losses	3,189	3,621
Total, Fair Value	64,880	224,019
Total, Unrealized Losses	$ 7,104	$ 12,499