| Investments In Available-For-Sale Securities And Other Cost Investments (Narrative) (Details) (USD $) In Millions, unless otherwise specified | 6 Months Ended | 1 Months Ended | |
|---|---|---|---|
| Jun. 30, 2013 | Jun. 30, 2012 | Jan. 18, 2013
 SIRIUS XM [Member] | |
| Purchase of shares in equity method investee | 50.0 | ||
| Payments to Acquire Investments | $ 2,584 | $ 207 | |
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- Definition Number of shares purchased in equity method investee No definition available. 
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| X | ||||||||||
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- Definition The cash outflow associated with the purchase of all investments (debt, security, other) during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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