v2.4.0.6
Pension Plans and Postretirement Benefits (Components of Benefits Expense)(Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Defined Benefit Plan Disclosure [Line Items]        
Benefit Plan Funding     $ 76  
Expected return on plan assets     5.00%  
Postretirement Benefits [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Service cost 8 8 16 15
Interest cost 8 8 15 15
Prior service cost 0 0 0 (13)
Other 0 0 0 0
Total benefits expense [Postretirement Benefits] 16 16 31 17
Pension Benefits [Member]
       
Defined Benefit Plan Disclosure [Line Items]        
Service cost 31 27 63 45
Interest cost 5 3 9 6
Prior service cost 0 0 0 0
Other (1) 0 (2) 0
Total benefits expense [Pension Benefits] $ 35 $ 30 $ 70 $ 51