Benefit Plans (Detail) - Pension Plans - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 38	$ 35	$ 106	$ 113
Interest cost	21	16	59	53
Expected return on plan assets	(52)	(40)	(146)	(129)
Amortization of prior service credit	(4)	(3)	(12)	(10)
Amortization of loss	17	22	48	73
Curtailment/Settlement (Gain) Loss	(1)	6	5	6
Net pension cost	$ 19	$ 36	$ 61	$ 106