| Defined Benefit Plans [Domain] |
Other Postretirement Benefit Plans, Defined Benefit [Member] |
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member] |
2007 |
Defined Benefit Plan Disclosure [Line Items] | Defined Benefit Plan, Assumptions Used in Calculations [Abstract] | Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract] | |
| Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components | 23,000,000 |
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components | 19,000,000 |
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation | 195,000,000 |
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation | 165,000,000 |