v2.4.0.6
Employee Benefits, Pension Plans With Benefit Obligations in Excess of Plan Assets (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]    
Projected benefit obligation $ 11,325 $ 11,030
Accumulated benefit obligation 11,321 11,019
Defined Benefit Plan, Fair Value of Plan Assets $ 9,061 $ 9,639