XML 154 R105.htm IDEA: XBRL DOCUMENT v2.4.0.6
Employee Retirement Benefits (Narratives) (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Net periodic benefit costs recognized $ 133 $ 118 $ 112
Contributions [Abstract]      
Estimated employer contributions in next fiscal year 48    
Assumptions Used [Abstract]      
Increase (decrease) in plan expense due to change in assumptions used 22 17 4
Pension Plans [Member]
     
Contributions [Abstract]      
Employer contributions 84 131  
Assumptions Used [Abstract]      
Decrease in the discount rate used to determine our obligation 0.80%    
Qualified Pension Plan [Member]
     
Contributions [Abstract]      
Employer contributions 76 124 42
Estimated employer contributions in next fiscal year 31    
Amount accumulated benefit obligation exceeded the fair value of plan assets 140 100  
Nonqualified Pension Plans [Member]
     
Contributions [Abstract]      
Employer contributions 8    
Estimated employer contributions in next fiscal year 9    
Supplemental Pension Plan of 2003 [Member]
     
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Maximum ratio of incentive compensation to base salary 50.00%    
Other Postretirement Plans [Member]
     
Contributions [Abstract]      
Employer contributions 6 6  
Estimated employer contributions in next fiscal year $ 8    
Assumptions Used [Abstract]      
Decrease in the discount rate used to determine our obligation 0.70%    
Equity Securities [Member]
     
Defined Benefit Plan, Assets, Target Allocations [Abstract]      
Minimum target plan asset allocations range 55.00%    
Maximum target plan asset allocations range 65.00%    
Fixed Income Securities [Member]
     
Defined Benefit Plan, Assets, Target Allocations [Abstract]      
Minimum target plan asset allocations range 35.00%    
Maximum target plan asset allocations range 45.00%    
Other Investments [Member]
     
Defined Benefit Plan, Assets, Target Allocations [Abstract]      
Maximum target plan asset allocations range 2.00%