Retirement and Post-Retirement Benefit Plans - Pension and Post-Retirement Benefit Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Amortization and deferrals:
Settlement loss	$ 214	$ 0	$ 0
Post-Retirement Benefit Plans
Net benefit (credit) cost
Service cost	1	1	1
Interest cost	11	17	15
Expected return on plan assets	(23)	(22)	(23)
Amortization and deferrals:
Actuarial loss (gain)	(10)	(31)	(17)
Prior service benefit	(12)	(13)	(18)
Net periodic (credit) benefit cost	(33)	(48)	(42)
Curtailment gain	0	0	0
Settlement loss	0	0	0
Special termination benefit cost	44	6	0
Total (credit) benefit cost	11	(42)	(42)
U.S. | Defined Benefit Plans
Net benefit (credit) cost
Service cost	0	0	0
Interest cost	412	491	452
Expected return on plan assets	(700)	(581)	(717)
Amortization and deferrals:
Actuarial loss (gain)	64	59	58
Prior service benefit	0	0	0
Net periodic (credit) benefit cost	(224)	(31)	(207)
Curtailment gain	0	0	0
Settlement loss	217	2	2
Special termination benefit cost	0	0	0
Total (credit) benefit cost	(7)	(29)	(205)
Non-U.S. | Defined Benefit Plans
Net benefit (credit) cost
Service cost	64	57	55
Interest cost	17	24	24
Expected return on plan assets	(43)	(37)	(39)
Amortization and deferrals:
Actuarial loss (gain)	43	31	28
Prior service benefit	(2)	(3)	(3)
Net periodic (credit) benefit cost	79	72	65
Curtailment gain	0	(22)	0
Settlement loss	1	1	5
Special termination benefit cost	0	0	0
Total (credit) benefit cost	$ 80	$ 51	$ 70