Accounts Payable, Accrued Liabilities and Other Liabilities - Components of Other Long-Term Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
Payables And Accruals [Abstract]
Employee benefit plan liabilities	$ 80	$ 92
Operating lease liabilities	84	89
Other accrued liabilities	115	105
Total	$ 279	$ 286