|
Supplemental Financial Information (Other Cash Flow Information) (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
Dec. 31, 2013
NBCUniversal Media, LLC [Member]
|
Dec. 31, 2012
NBCUniversal Media, LLC [Member]
|
Jan. 28, 2011
NBCUniversal Media, LLC [Member]
|
Dec. 31, 2013
Successor [Member]
NBCUniversal Media, LLC [Member]
|
Dec. 31, 2012
Successor [Member]
NBCUniversal Media, LLC [Member]
|
Dec. 31, 2011
Successor [Member]
NBCUniversal Media, LLC [Member]
|
Jan. 28, 2011
Successor [Member]
NBCUniversal Media, LLC [Member]
|
Jan. 28, 2011
Predecessor [Member]
NBCUniversal Media, LLC [Member]
|
Dec. 31, 2010
Predecessor [Member]
NBCUniversal Media, LLC [Member]
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cash and cash equivalents, beginning of year | $ 1,718 | $ 10,951 | $ 1,620 | $ 5,984 | $ 967 | $ 5,921 | $ 967 | $ 5,921 | $ 808 | $ 508 | $ 470 | $ 1,084 | |
| Comcast Content Business Contributed Cash Balances | 38 | ||||||||||||
| Cash and cash equivalents, end of year | $ 1,718 | $ 10,951 | $ 1,620 | $ 5,984 | $ 967 | $ 5,921 | $ 967 | $ 5,921 | $ 808 | $ 508 | $ 470 | $ 1,084 |