v3.21.2
Pension and Other Postretirement Benefits - Benefit Obligations in Excess of Plan Assets (Detail) - USD ($)
$ in Millions
Sep. 30, 2021
Sep. 30, 2020
U.S. Plans    
Accumulated benefit obligation in excess of plan assets    
Accumulated benefit obligation at end of period $ (6) $ (7)
Fair value of plan assets at end of period 0 0
Projected benefit obligation in excess of plan assets    
Benefit obligation at end of period (6) (7)
Fair value of plan assets at end of period 0 0
Non-U.S. Plans    
Accumulated benefit obligation in excess of plan assets    
Accumulated benefit obligation at end of period (520) (563)
Fair value of plan assets at end of period 548 525
Projected benefit obligation in excess of plan assets    
Benefit obligation at end of period (520) (563)
Fair value of plan assets at end of period $ 548 $ 525