|
Derivative instruments (Details 4) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
|
Dec. 31, 2012
|
|---|---|---|
| Assets | ||
| Total derivative assets, fair value | $ 138 | $ 111 |
| Liabilities | ||
| Total derivative liabilities, fair value | 93 | 65 |
|
Derivatives designated as hedging instrument [Member]
|
||
| Assets | ||
| Total derivative assets, fair value | 137 | 110 |
| Liabilities | ||
| Total derivative liabilities, fair value | 93 | 64 |
|
Derivatives not designated as hedging instrument [Member]
|
||
| Assets | ||
| Total derivative assets, fair value | 1 | 1 |
| Liabilities | ||
| Total derivative liabilities, fair value | 0 | 1 |
|
Cross currency swap contracts [Member] | Other current assets/Other noncurrent assets [Member] | Derivatives designated as hedging instrument [Member]
|
||
| Assets | ||
| Total derivative assets, fair value | 8 | 65 |
|
Cross currency swap contracts [Member] | Accrued liabilities/Other noncurrent liabilities [Member] | Derivatives designated as hedging instrument [Member]
|
||
| Liabilities | ||
| Total derivative liabilities, fair value | 72 | 6 |
|
Foreign currency contracts [Member] | Other current assets/Other noncurrent assets [Member] | Derivatives designated as hedging instrument [Member]
|
||
| Assets | ||
| Total derivative assets, fair value | 107 | 45 |
|
Foreign currency contracts [Member] | Other current assets [Member] | Derivatives not designated as hedging instrument [Member]
|
||
| Assets | ||
| Total derivative assets, fair value | 1 | 1 |
|
Foreign currency contracts [Member] | Accrued liabilities/Other noncurrent liabilities [Member] | Derivatives designated as hedging instrument [Member]
|
||
| Liabilities | ||
| Total derivative liabilities, fair value | 21 | 58 |
|
Foreign currency contracts [Member] | Accrued liabilities [Member] | Derivatives not designated as hedging instrument [Member]
|
||
| Liabilities | ||
| Total derivative liabilities, fair value | 0 | 1 |
|
Interest rate swap contracts [Member] | Other current assets/Other noncurrent assets [Member] | Derivatives designated as hedging instrument [Member]
|
||
| Assets | ||
| Total derivative assets, fair value | 22 | |
|
Interest rate swap contracts [Member] | Accrued liabilities/Other noncurrent liabilities [Member] | Derivatives designated as hedging instrument [Member]
|
||
| Liabilities | ||
| Total derivative liabilities, fair value | $ 0 |