|
Investments (Investment Income (Loss), Net) (Details) (USD $)
|
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2014
|
Sep. 30, 2013
|
Sep. 30, 2014
|
Sep. 30, 2013
|
|
| Gains on sales and exchanges of investments, net | $ 3,000,000 | $ 445,000,000 | $ 176,000,000 | $ 483,000,000 |
| Investment impairment losses | (6,000,000) | (12,000,000) | (30,000,000) | (25,000,000) |
| Unrealized gains (losses) on securities underlying prepaid forward sale agreements | 15,000,000 | 345,000,000 | (13,000,000) | 1,197,000,000 |
| Mark to market adjustments on derivative component of prepaid forward sale agreements and indexed debt instruments | (13,000,000) | (348,000,000) | 19,000,000 | (1,189,000,000) |
| Interest and dividend income | 29,000,000 | 28,000,000 | 85,000,000 | 84,000,000 |
| Other, net | (7,000,000) | 6,000,000 | 17,000,000 | (1,000,000) |
| Investment income (loss), net | 21,000,000 | 464,000,000 | 254,000,000 | 549,000,000 |
|
NBCUniversal Media, LLC [Member]
|
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| Investment income (loss), net | $ 3,000,000 | $ 1,000,000 | $ 18,000,000 | $ 9,000,000 |