| **Fair Value Measurements And Financial Instruments (Tables)**          | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
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| **Fair Value Disclosures [Abstract]**                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Summary Of Components Of Available-For-Sale Securities                  | The following table summarizes the components of the balance of the Company’s available-for-sale securities at June 29, 2013 and December 29, 2012 (in millions): June 29, 2013 December 29, 2012Adjusted cost$8 $9Gross unrealized gains29 32Fair value$37 $41                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Summary Of Financial Assets Measured At Fair Value On A Recurring Basis | A summary of financial assets measured at fair value on a recurring basis at June 29, 2013 and December 29, 2012 is as follows (in millions): Balance SheetClassificationJune 29, 2013 Quoted PricesIn ActiveMarkets(Level 1) SignificantOtherObservableInputs(Level 2) SignificantUnobservableInputs(Level 3)Assets        Money-market securitiesCash and cash equivalents$884 $884 $— $—Available-for-sale securitiesOther current assets37 37 — —Trading securitiesOther assets253 253 — —Total assets $1,174 $1,174 $— $— Balance SheetClassificationDecember 29, 2012 Quoted PricesIn ActiveMarkets(Level 1) SignificantOtherObservableInputs(Level 2) SignificantUnobservableInputs(Level 3)Assets        Money-market securitiesCash and cash equivalents$964 $964 $— $—Available-for-sale securitiesOther current assets41 41 — —Trading securitiesOther assets231 231 — —Total assets $1,236 $1,236 $— $— |

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| - Definition
Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value.
+ References
No definition available.
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| - Definition
Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3).
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19190-110258
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