v2.4.0.6
Employee Benefit Plans (Tables)
6 Months Ended
Jun. 30, 2012
Employee Benefit Plans  
Components of Net Periodic Benefit Expense
   Three Months Ended Six Months Ended
   June 30, June 30,
   2012 2011 2012 2011
          
   (dollars in millions)
Service cost, benefits earned during the period $ 7$ 8$ 15$ 16
Interest cost on projected benefit obligation   41  41  82  83
Expected return on plan assets   (27)  (33)  (55)  (66)
Net amortization of prior service costs   (4)  (4)  (7)  (8)
Net amortization of actuarial loss   7  5  14  10
 Net periodic benefit expense $ 24$ 17$ 49$ 35