Amortized Cost and Fair Value of Available for Sale Securities by Expected Maturity (Detail) (USD $)	Mar. 30, 2013	Dec. 29, 2012
Amortized Cost
Due in one year or less	$ 887,725,000	$ 792,946,000
Due after one year through five years	3,159,145,000	2,725,036,000
Due after five years through ten years	474,711,000	520,800,000
Due after ten years	212,661,000	218,695,000
Total	4,734,242,000	4,257,477,000
Amortized cost of available-for-sale securities	5,477,386,000	4,938,090,000
Fair Value
Due in one year or less	892,094,000	797,260,000
Due after one year through five years	3,191,548,000	2,755,043,000
Due after five years through ten years	479,469,000	526,924,000
Due after ten years	219,478,000	226,703,000
Total	4,782,589,000	4,305,930,000
Fair value of available-for-sale securities	5,624,656,000	5,033,106,000
Restricted investments
Amortized Cost
Amortized cost of available-for-sale securities	170,000,000	170,000,000
Fair Value
Fair value of available-for-sale securities	170,604,000	170,431,000
Equity securities
Amortized Cost
Amortized cost of available-for-sale securities	573,144,000	510,613,000
Fair Value
Fair value of available-for-sale securities	$ 671,463,000	$ 556,745,000