v2.4.0.6
Employee Benefits, Changes in Benefit Obligation and Plan Assets (Details) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Change in plan assets:      
Fair value of plan assets at end of year $ 9,061 $ 9,639  
Pension benefits qualified [Member]
      
Change in benefit obligation:      
Service cost 6 5 210
Interest cost 520 554 595
Change in plan assets:      
Funded status at end of year (1,573) (698)  
Liabilities, amounts recognized in balance sheet at end of year (1,573) (698)  
Pension benefits qualified [Member] | Change in benefit obligation [Member]
      
Change in benefit obligation:      
Benefit obligation at beginning of year 10,337 10,038  
Service cost 6 5  
Interest cost 520 554  
Plan participants' contributions 0 0  
Amendments 0 2  
Actuarial loss (gain) 501 386  
Benefits paid (726) (652)  
Curtailments (3) 0  
Liability transfer 0 0  
Foreign exchange impact (1) 4  
Benefit obligation at end of year 10,634 10,337  
Pension benefits qualified [Member] | Change in plan assets [Member]
      
Change in benefit obligation:      
Plan participants' contributions 0 0  
Benefits paid (726) (652)  
Foreign exchange impact (1) 4  
Change in plan assets:      
Fair value of plan assets at beginning of year 9,639 9,112  
Actual return on plan assets 139 1,163  
Employer contribution 10 12  
Fair value of plan assets at end of year 9,061 9,639  
Pension benefits non-qualified [Member]
      
Change in benefit obligation:      
Service cost 1 0 8
Interest cost 34 37 43
Change in plan assets:      
Funded status at end of year (691) (693)  
Liabilities, amounts recognized in balance sheet at end of year (691) (693)  
Pension benefits non-qualified [Member] | Change in benefit obligation [Member]
      
Change in benefit obligation:      
Benefit obligation at beginning of year 693 681  
Service cost 1 0  
Interest cost 34 37  
Plan participants' contributions 0 0  
Amendments 0 0  
Actuarial loss (gain) 33 46  
Benefits paid (70) (71)  
Curtailments 0 0  
Liability transfer 0 0  
Foreign exchange impact 0 0  
Benefit obligation at end of year 691 693  
Pension benefits non-qualified [Member] | Change in plan assets [Member]
      
Change in benefit obligation:      
Plan participants' contributions 0 0  
Benefits paid (70) (71)  
Foreign exchange impact 0 0  
Change in plan assets:      
Fair value of plan assets at beginning of year 0 0  
Actual return on plan assets 0 0  
Employer contribution 70 71  
Fair value of plan assets at end of year 0 0  
Other benefits [Member]
      
Change in benefit obligation:      
Service cost 13 13 13
Interest cost 71 78 83
Change in plan assets:      
Fair value of plan assets at beginning of year 697    
Fair value of plan assets at end of year 640 697  
Funded status at end of year (664) (701)  
Liabilities, amounts recognized in balance sheet at end of year (664) (701)  
Other benefits [Member] | Change in benefit obligation [Member]
      
Change in benefit obligation:      
Benefit obligation at beginning of year 1,398 1,401  
Service cost 13 13  
Interest cost 71 78  
Plan participants' contributions 88 74  
Amendments 0 0  
Actuarial loss (gain) (105) (5)  
Benefits paid (161) (147)  
Curtailments 0 0  
Liability transfer 0 (17)  
Foreign exchange impact 0 1  
Benefit obligation at end of year 1,304 1,398  
Other benefits [Member] | Change in plan assets [Member]
      
Change in benefit obligation:      
Plan participants' contributions 88 74  
Benefits paid (161) (147)  
Foreign exchange impact 0 0  
Change in plan assets:      
Fair value of plan assets at beginning of year 697 376  
Actual return on plan assets 10 33  
Employer contribution 6 361  
Fair value of plan assets at end of year $ 640 $ 697