v3.6.0.2
Postretirement Benefit Plans - Components of Net Periodic Pension Costs (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Pension and Other Postretirement Benefit Expense [Abstract]      
Service cost $ 17 $ 12 $ 10
Interest cost on the projected benefit obligation 14 11 13
Expected return on plan assets (6) (6) (7)
Amortization of net (gain) loss 2 3 (1)
Curtailments and settlements (1) (6)  
Other   2  
Net periodic cost $ 26 $ 16 $ 15