Available for Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 28, 2013	Dec. 29, 2012
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 5,836,904	$ 4,938,090
Gross Unrealized Gains	172,348	110,516
Gross Unrealized Losses	17,766	15,500
Fair Value	5,991,486	5,033,106
Tax exempt bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,430,028	3,115,963
Gross Unrealized Gains	25,588	33,787
Gross Unrealized Losses	9,917	2,646
Fair Value	3,445,699	3,147,104
Taxable bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,445,901	1,141,514
Gross Unrealized Gains	7,641	17,667
Gross Unrealized Losses	3,863	355
Fair Value	1,449,679	1,158,826
Restricted investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	170,000	170,000
Gross Unrealized Gains	0	431
Gross Unrealized Losses	86	0
Fair Value	169,914	170,431
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	790,975	510,613
Gross Unrealized Gains	139,119	58,631
Gross Unrealized Losses	3,900	12,499
Fair Value	$ 926,194	$ 556,745