Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Narrative (Details)

v2.4.0.6
Employee Benefit Plans - Narrative (Details) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]      
Prior Years Market Gains Losses Recognized By Asset Valuation Method For Qualified Pension Plans 60.00%    
Remaining Market Gains Losses Recognized By Asset Valuation Method For Qualified Pension Plans 40.00%    
Unrecognized Gain Loss Percentage For Post Retirement Health Care Plan 50.00%    
Defined Benefit Plan Decline in Rates Threshold to Analyze Significant Impact to Plan, Percent 0.25%    
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components $ 4    
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation 59    
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components 3    
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation 52    
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]      
Contribution To Qualified Defined Contribution Plans Cash 723 670 605
Common Stock Held By Defined Contribution Plans Shares 232 208  
Payments To Plans For Dividends On Common Stock 9 8 8
Nonqualified and Other Pension Plans [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year 124    
Weighted-Average Assumptions, Expected Return on Plan Assets 5.25% 5.25% 5.25%
Qualified Pension Plans [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Increase In Plan Assets With Respect To Decline In Discount Rate 55    
Increase In Plan Assets With Respect To Decline In Expected Return 27    
Weighted-Average Assumptions, Expected Return on Plan Assets 8.00% 8.00% 8.00%
Defined Benefit Plan, Amount of Employer and Related Party Securities Included in Plan Assets 82 189  
Defined Benefit Plan, Equity Securities 0.55% 1.21%  
Postretirement Health and Life Plans [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year 115    
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year 8.00%    
Reduction In Assumed Health Care Cost Trend Rate 5.00%    
Weighted-Average Assumptions, Expected Return on Plan Assets 8.00% 8.00% 8.00%
Equity Securities
      
Defined Benefit Plan Disclosure [Line Items]      
Weighted-Average Assumptions, Expected Return on Plan Assets 8.75%    
Non-U.S. Pension Plans [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year $ 98    
Weighted-Average Assumptions, Expected Return on Plan Assets 6.58% 6.60% 6.78%
Debt Securities [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Weighted-Average Assumptions, Expected Return on Plan Assets 5.75%    
Real Estate [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Weighted-Average Assumptions, Expected Return on Plan Assets 7.00%