|
Divestitures (Details) (USD $)
In Millions, unless otherwise specified |
6 Months Ended | |
|---|---|---|
|
Jun. 30, 2013
|
Jun. 30, 2012
|
|
| Divestitures [Abstract] | ||
| Proceeds from Sales of Producing Properties and Acreage | $ 580 | $ 1,112 |