|
Summary of Significant Accounting Policies (Accumulated Other Comprehensive Loss) (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
|---|---|---|
| Pension and other employee benefit plans | $ (7,833) | $ (7,008) |
| Foreign exchange translation | 60 | 25 |
| Cash flow hedges and interest rate locks | (5) | (13) |
| Unrealized gain (loss) on investments, and other | (10) | (5) |
| Total | $ (7,788) | $ (7,001) |