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 Components23,000,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components19,000,000
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation195,000,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation165,000,000