Retirement and Post-Retirement Benefit Plans - Schedule of Pension and Post-Retirement Benefit (Credit) Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Post-Retirement Benefit Plans
Retirement and post-retirement benefit plans
Service cost	$ 0	$ 0	$ 1	$ 0
Interest cost	3	4	8	12
Expected return on plan assets	(6)	(5)	(17)	(15)
Amortization and deferrals:
Actuarial loss (gain)	(3)	(8)	(8)	(24)
Prior service benefit	(3)	(3)	(9)	(9)
Net periodic (credit) benefit cost	(9)	(12)	(25)	(36)
Curtailment gain	0	0	0	0
Settlement loss	0	0	0	0
Special termination benefit cost			44	0
Total periodic benefit (credit) cost	(9)	(12)	19	(36)
U.S. | Defined Benefit Plans
Retirement and post-retirement benefit plans
Service cost	0	0	0	0
Interest cost	103	123	309	369
Expected return on plan assets	(175)	(146)	(525)	(437)
Amortization and deferrals:
Actuarial loss (gain)	16	15	48	45
Prior service benefit	0	0	0	0
Net periodic (credit) benefit cost	(56)	(8)	(168)	(23)
Curtailment gain	0	0	0	0
Settlement loss	2	1	3	2
Special termination benefit cost			0	0
Total periodic benefit (credit) cost	(54)	(7)	(165)	(21)
Non-U.S. | Defined Benefit Plans
Retirement and post-retirement benefit plans
Service cost	16	14	47	43
Interest cost	4	6	13	18
Expected return on plan assets	(10)	(9)	(31)	(28)
Amortization and deferrals:
Actuarial loss (gain)	11	8	32	24
Prior service benefit	(1)	(1)	(2)	(2)
Net periodic (credit) benefit cost	20	18	59	55
Curtailment gain	0	(9)	0	(9)
Settlement loss	0	0	0	0
Special termination benefit cost			0	0
Total periodic benefit (credit) cost	$ 20	$ 9	$ 59	$ 46