Temporarily Impaired Available for Sale Securities by Time Period Impaired (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	$ 1,238,851	$ 858,549
Less Than 12 Months, Unrealized Losses	13,642	11,879
12 Months or Longer, Fair Value	129,504	14,260
12 Months or Longer, Unrealized Losses	4,124	3,621
Total, Fair Value	1,368,355	872,809
Total, Unrealized Losses	17,766	15,500
Tax exempt bonds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	502,304	566,914
Less Than 12 Months, Unrealized Losses	6,710	2,646
12 Months or Longer, Fair Value	106,985	0
12 Months or Longer, Unrealized Losses	3,207	0
Total, Fair Value	609,289	566,914
Total, Unrealized Losses	9,917	2,646
Taxable bonds
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	535,233	81,876
Less Than 12 Months, Unrealized Losses	3,347	355
12 Months or Longer, Fair Value	19,367	0
12 Months or Longer, Unrealized Losses	516	0
Total, Fair Value	554,600	81,876
Total, Unrealized Losses	3,863	355
Restricted investments
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	169,914
Less Than 12 Months, Unrealized Losses	86
12 Months or Longer, Fair Value	0
12 Months or Longer, Unrealized Losses	0
Total, Fair Value	169,914
Total, Unrealized Losses	86
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair Value	31,400	209,759
Less Than 12 Months, Unrealized Losses	3,499	8,878
12 Months or Longer, Fair Value	3,152	14,260
12 Months or Longer, Unrealized Losses	401	3,621
Total, Fair Value	34,552	224,019
Total, Unrealized Losses	$ 3,900	$ 12,499