Benefit Plans (Detail) - Pension Plans - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 24	$ 35
Interest cost	35	20
Expected return on plan assets	(38)	(48)
Amortization of prior service credit	(2)	(4)
Amortization of loss	17	16
Settlements	0	5
Net pension cost	$ 36	$ 24