Investments (Amortized Cost And Fair Value Of Debt And Equity Securities Classified As AFS By Maturities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 25, 2010
Amortized Cost
Due in one year or less	$ 445,296	$ 332,992
Due after one year through five years	2,492,484	1,499,176
Due after five years through ten years	348,427	337,677
Due after ten years	428,064	630,051
Available-for-sale securities, debt maturities, Amortized Cost	3,714,271	2,799,896
Total Amortized Cost	4,180,376	3,019,633
Fair Value
Due in one year or less	447,972	336,282
Due after one year through five years	2,524,020	1,506,731
Due after five years through ten years	356,808	335,056
Due after ten years	440,079	640,379
Available-for-sale securities, debt maturities, Fair Value	3,768,879	2,818,448
Fair Value of available-for-sale securities	4,253,255	3,096,033
Restricted Investments [Member]
Amortized Cost
Total Amortized Cost	170,000
Fair Value
Fair Value of available-for-sale securities	166,981
Equity Securities [Member]
Amortized Cost
Total Amortized Cost	296,105	219,737
Fair Value
Fair Value of available-for-sale securities	$ 317,395	$ 277,585