Employee Benefit Plans - Additional Information (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($) Plan
Defined Benefit Plan Disclosure [Line Items]
Number of foreign defined benefit plans | Plan					1
Pre-tax gain from net pension obligations					$ 7
Additional charge on defined benefit plan actuarial gain (loss)					3
Defined contribution plans expenses			$ 18	$ 19	20
Pension Benefits [Member] | Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contribution		$ 3
Postretirement Benefits [Member] | Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Postretirement medical benefits		3
U.S. Defined Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 99		3	99
Settlement loss	$ 3
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement Gain (Loss), Statement of Income or Comprehensive Income [Extensible List]	Other income (expense)
Pension benefit obligation decreased			106
U.S. Defined Benefit Plans [Member] | Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement loss		$ 4
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement Gain (Loss), Statement of Income or Comprehensive Income [Extensible List]		Other income (expense)
U.S. Defined Benefit Plans [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement loss			4	3
Pre-tax gain from net pension obligations	$ (6)		(1)	(6)
U.S. Defined Benefit Plans [Member] | Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Pre-tax gain from net pension obligations	4		4	4
Foreign Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	215		$ 209	215
Pension benefit obligation decreased				47
Foreign Plans [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of weighted-average target asset allocation			21.00%
Foreign Plans [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of weighted-average target asset allocation			73.00%
Foreign Plans [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of weighted-average target asset allocation			2.00%
Foreign Plans [Member] | Cash and Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of weighted-average target asset allocation			4.00%
Foreign Plans [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement loss			$ 1	1	(7)
Pre-tax gain from net pension obligations	(40)		(20)	(40)
Foreign Plans [Member] | Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Pre-tax gain from net pension obligations	$ (4)		$ (2)	$ (4)
U.K. Plan [Member] | Other Nonoperating Income (Expense) [Member]
Defined Benefit Plan Disclosure [Line Items]
Charge on effect of accrued benefit					$ 2