Temporarily Impaired Available for Sale Securities by Time Period Impaired (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 29, 2013	Dec. 29, 2012
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	$ 2,518,242	$ 858,549
Less Than 12 Months, Unrealized Losses	37,913	11,879
12 Months or Longer, Fair Value	8,212	14,260
12 Months or Longer, Unrealized Losses	2,185	3,621
Total, Fair Value	2,526,454	872,809
Total, Unrealized Losses	40,098	15,500
Tax exempt bonds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	1,563,819	566,914
Less Than 12 Months, Unrealized Losses	21,876	2,646
12 Months or Longer, Fair Value	0	0
12 Months or Longer, Unrealized Losses	0	0
Total, Fair Value	1,563,819	566,914
Total, Unrealized Losses	21,876	2,646
Taxable bonds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	672,118	81,876
Less Than 12 Months, Unrealized Losses	6,713	355
12 Months or Longer, Fair Value	0	0
12 Months or Longer, Unrealized Losses	0	0
Total, Fair Value	672,118	81,876
Total, Unrealized Losses	6,713	355
Restricted investments
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	169,396
Less Than 12 Months, Unrealized Losses	604
12 Months or Longer, Fair Value	0
12 Months or Longer, Unrealized Losses	0
Total, Fair Value	169,396
Total, Unrealized Losses	604
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	112,909	209,759
Less Than 12 Months, Unrealized Losses	8,720	8,878
12 Months or Longer, Fair Value	8,212	14,260
12 Months or Longer, Unrealized Losses	2,185	3,621
Total, Fair Value	121,121	224,019
Total, Unrealized Losses	$ 10,905	$ 12,499