| Investments In Affiliates Accounted For Using The Equity Method (Narrative) (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended | 1 Months Ended | 3 Months Ended | 9 Months Ended | 1 Months Ended | 3 Months Ended | 9 Months Ended | |||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013
 Sirius XM Canada [Member] | Sep. 30, 2012
 Sirius XM Canada [Member] | Sep. 30, 2013
 Sirius XM Canada [Member] | Sep. 30, 2012
 Sirius XM Canada [Member] | Sep. 30, 2013
 Live Nation [Member] | Sep. 30, 2012
 Live Nation [Member] | Sep. 30, 2013
 Live Nation [Member] | Sep. 30, 2012
 Live Nation [Member] | May 01, 2013
 Live Nation [Member] | Sep. 30, 2013
 SIRIUS XM [Member] | Sep. 30, 2012
 SIRIUS XM [Member] | Sep. 30, 2013
 SIRIUS XM [Member] | Sep. 30, 2012
 SIRIUS XM [Member] | May 01, 2013
 Charter Communications [Member] | Sep. 30, 2013
 Charter Communications [Member] | Sep. 30, 2012
 Charter Communications [Member] | Sep. 30, 2013
 Charter Communications [Member] | Sep. 30, 2012
 Charter Communications [Member] | Jan. 18, 2013
 SIRIUS XM [Member] | Mar. 31, 2013
 Live Nation [Member] | Sep. 30, 2013
 SIRIUS XM [Member] | May 01, 2013
 SIRIUS XM [Member] | Jan. 18, 2013
 SIRIUS XM [Member]
 Deferred revenue [Member] | |||||||||||||||||
| Subscriber fee royalty percentage | 15.00% | ||||||||||||||||||||||||||||||||||||||||||
| Purchase of shares in equity method investee | 26.9 | 50.0 | 1.7 | ||||||||||||||||||||||||||||||||||||||||
| Deferred Income Tax Expense (Benefit) | $ (190,000,000) | $ 501,000,000 | |||||||||||||||||||||||||||||||||||||||||
| Equity Method Investment, Quoted Market Value | 385,000,000 | 385,000,000 | 966,000,000 | [1] | 966,000,000 | [1] | 3,619,000,000 | [1] | 3,619,000,000 | [1] | |||||||||||||||||||||||||||||||||
| Income (Loss) from Equity Method Investments | (8,000,000) | 14,000,000 | (12,000,000) | 1,307,000,000 | 2,000,000 | [2] | 0 | 3,000,000 | [2] | 0 | 13,000,000 | 14,000,000 | 5,000,000 | (2,000,000) | 0 | [2] | (5,000,000) | 8,000,000 | [2] | 1,304,000,000 | (37,000,000) | [3] | 0 | (74,000,000) | [2] | 0 | |||||||||||||||||
| Broadcast rights | 70,000,000 | ||||||||||||||||||||||||||||||||||||||||||
| Investments, Fair Value Disclosure | 21,000,000 | ||||||||||||||||||||||||||||||||||||||||||
| Due to Related Parties, Current | 40,000,000 | ||||||||||||||||||||||||||||||||||||||||||
| Due to Related Parties | 21,000,000 | ||||||||||||||||||||||||||||||||||||||||||
| Revenue from Related Parties | 34,000,000 | ||||||||||||||||||||||||||||||||||||||||||
| Warrants acquired | 1.1 | ||||||||||||||||||||||||||||||||||||||||||
| Business Acquisition, Cost of Acquired Entity, Purchase Price | 2,600,000,000 | ||||||||||||||||||||||||||||||||||||||||||
| Equity Method Investment, Ownership Percentage | 38.00% | [2] | 38.00% | [2] | 26.00% | [4] | 26.00% | [4] | 27.00% | 26.00% | [3] | 26.00% | [3] | ||||||||||||||||||||||||||||||
| Subsidiary or Equity Method Investee, Price-Per-Share | $ 95.50 | ||||||||||||||||||||||||||||||||||||||||||
| Equity method investment, cash paid for acquisition | 1,200,000,000 | ||||||||||||||||||||||||||||||||||||||||||
| shares underlying borrowed share position, unwound | 8.1 | 20.3 | 720.0 | ||||||||||||||||||||||||||||||||||||||||
| Equity Method Investment, Difference Between Carrying Amount and Underlying Equity | $ 3,000,000,000 | ||||||||||||||||||||||||||||||||||||||||||
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