|
Fair Value Measurements and Financial Instruments (Details) (USD $)
In Millions, except Per Share data, unless otherwise specified |
12 Months Ended | ||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2011
|
Dec. 31, 2011
Fair Value
Money market funds and highly liquid debt securities
Recurring
|
Dec. 31, 2010
Fair Value
Money market funds and highly liquid debt securities
Recurring
|
Dec. 31, 2011
Fair Value
Corporate bonds
Recurring
|
Dec. 31, 2010
Fair Value
Corporate bonds
Recurring
|
Dec. 31, 2011
Fair Value
Government bonds.
Recurring
|
Dec. 31, 2010
Fair Value
Government bonds.
Recurring
|
Dec. 31, 2011
Fair Value
Interest rate contracts
Recurring
|
Dec. 31, 2010
Fair Value
Interest rate contracts
Recurring
|
Dec. 31, 2011
Fair Value
Foreign exchange contracts
Recurring
|
Dec. 31, 2010
Fair Value
Foreign exchange contracts
Recurring
|
Dec. 31, 2011
Quoted Prices in Active Markets for Identical Assets (Level 1)
Money market funds and highly liquid debt securities
Recurring
|
Dec. 31, 2010
Quoted Prices in Active Markets for Identical Assets (Level 1)
Money market funds and highly liquid debt securities
Recurring
|
Dec. 31, 2011
Significant Other Observable Inputs (Level 2)
Money market funds and highly liquid debt securities
Recurring
|
Dec. 31, 2010
Significant Other Observable Inputs (Level 2)
Money market funds and highly liquid debt securities
Recurring
|
Dec. 31, 2011
Significant Other Observable Inputs (Level 2)
Government bonds.
Recurring
|
Dec. 31, 2010
Significant Other Observable Inputs (Level 2)
Government bonds.
Recurring
|
Dec. 31, 2011
Significant Other Observable Inputs (Level 2)
Interest rate contracts
Recurring
|
Dec. 31, 2010
Significant Other Observable Inputs (Level 2)
Interest rate contracts
Recurring
|
Dec. 31, 2011
Significant Other Observable Inputs (Level 2)
Foreign exchange contracts
Recurring
|
Dec. 31, 2010
Significant Other Observable Inputs (Level 2)
Foreign exchange contracts
Recurring
|
Dec. 31, 2011
Significant Unobservable (Level 3) Inputs
Corporate bonds
Recurring
|
Dec. 31, 2010
Significant Unobservable (Level 3) Inputs
Corporate bonds
Recurring
|
|
| Fair Value Measurements and Financial Instruments | |||||||||||||||||||||||
| Net assets value (in dollar per share) | $ 1 | ||||||||||||||||||||||
| Assets: | |||||||||||||||||||||||
| Money market funds and highly liquid debt securities | $ 2,428 | $ 2,618 | $ 2,403 | $ 2,591 | $ 25 | $ 27 | |||||||||||||||||
| Other investments | 12 | 12 | 3 | 3 | 3 | 3 | 12 | 12 | |||||||||||||||
| Derivatives | 16 | 15 | 141 | 159 | 16 | 15 | 141 | 159 | |||||||||||||||
| Liabilities: | |||||||||||||||||||||||
| Derivatives | $ 189 | $ 158 | $ 189 | $ 158 |