Retirement Benefit Plans (Details) - Benefit Plans - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 25	$ 23	$ 49	$ 46
Interest cost	30	35	59	71
Expected return on plan assets	(120)	(134)	(239)	(269)
Amortization and deferrals:
Actuarial loss	75	65	149	129
Prior service benefit	(4)	(4)	(7)	(7)
Net periodic benefit (credit) cost	6	(15)	11	(30)
Settlement loss	0	1	1	1
Special termination benefits	2	1	2	1
Total net benefit (credit) cost	$ 8	$ (13)	$ 14	$ (28)