v2.4.0.6
Postretirement Benefit Plans - Components of Net Periodic Pension Costs (Detail) (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]      
Service cost $ 11 $ 12 $ 12
Interest cost on the projected benefit obligation 14 15 15
Expected return on plan assets (6) (6) (6)
Amortization of prior service cost         
Amortization of net (gain) loss     (1)
Curtailments & settlements (2) (1) (1)
Other 1   1
Net periodic cost $ 18 $ 20 $ 20