Investments (Fair Value Method Investments) (Details) - USD ($) shares in Millions, $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Fair value equity securities held as collateral | $ 523 | ||
| Obligations under prepaid forward sale agreements | 119 | ||
| Derivative component of prepaid forward sale agreements | 356 | ||
| Total liabilities associated with prepaid forward sales agreements | $ 0 | 475 | |
| Proceeds From Sales Of Businesses And Investments | $ 433 | $ 666 | $ 1,083 |
| Clearwire LLC [Member] | |||
| Proceeds from sale of available-for-sale securities | $ 443 | ||
| Fair Value Investment Shares Sold | 89.0 | ||
| Pre-tax gain realized on Clearwire | $ 443 | ||
| Liberty Media Redemption Transaction [Member] | |||
| Shares Redeemed | 6.3 | ||
| Fair value of the shares delivered in the Liberty Media exchange transaction | $ 937 | ||
| Proceeds From Sales Of Businesses And Investments | $ 417 | ||