v2.4.0.6
Pension And Other Postretirement Benefits (Fair Value Of Benefit Plan Assets- Other Postretirement) (Details) (Other Postretirement Benefits [Member], USD $)
In Millions, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 538 $ 558 $ 514
U.S. Equity Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 166 180  
Non-U.S. Equity Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 155 191  
Private Equity [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 7 5  
Corporate Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 77 49  
Government Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 120 117  
Asset-Backed Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 12 13  
Private Mortgages Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   2  
Cash [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1 1  
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   1  
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Cash [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   1  
Significant Other Observable Inputs (Level 2) [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 531 550  
Significant Other Observable Inputs (Level 2) [Member] | U.S. Equity Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 166 [1] 180 [1]  
Significant Other Observable Inputs (Level 2) [Member] | Non-U.S. Equity Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 155 [1] 191 [1]  
Significant Other Observable Inputs (Level 2) [Member] | Corporate Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 77 [2] 49 [2]  
Significant Other Observable Inputs (Level 2) [Member] | Government Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 120 [2] 117 [2]  
Significant Other Observable Inputs (Level 2) [Member] | Asset-Backed Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 12 [2] 13 [2]  
Significant Other Observable Inputs (Level 2) [Member] | Cash [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1    
Significant Unobservable Inputs (Level 3) [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 7 7  
Significant Unobservable Inputs (Level 3) [Member] | Private Equity [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 7 [3] 5 [3]  
Significant Unobservable Inputs (Level 3) [Member] | Private Mortgages Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets   $ 2 [4]  
[1] For U.S. and non-U.S. equity securities held in the form of fund units that are redeemable at the measurement date, the unit value is treated as a Level 2 input. The fair value of the securities owned by the funds is based on observable quoted prices on active exchanges, which are Level 1 inputs.
[2] For corporate, government and asset-backed debt securities, fair value is based on observable inputs of comparable market transactions.
[3] For private equity, fair value is generally established by using revenue or earnings multiples or other relevant market data including Initial Public Offerings.
[4] For private mortgages, fair value is based on proprietary credit spread matrices developed using market data and monthly surveys of active mortgage bankers.