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, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Post-Retirement Benefit Plans
Retirement and post-retirement benefit plans
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	4	4	12	12
Expected return on plan assets	(5)	(6)	(15)	(18)
Amortization and deferrals:
Actuarial loss (gain)	(8)	(4)	(24)	(12)
Prior service benefit	(3)	(5)	(9)	(15)
Net periodic (credit) benefit cost	(12)	(11)	(36)	(33)
Curtailment gain	0	0	0	0
Settlement loss	0	0	0	0
Total periodic benefit (credit) cost	(12)	(11)	(36)	(33)
U.S. | Defined Benefit Plans
Retirement and post-retirement benefit plans
Service cost	0	0	0	0
Interest cost	123	113	369	339
Expected return on plan assets	(146)	(180)	(437)	(540)
Amortization and deferrals:
Actuarial loss (gain)	15	14	45	45
Prior service benefit	0	0	0	0
Net periodic (credit) benefit cost	(8)	(53)	(23)	(156)
Curtailment gain	0	0	0	0
Settlement loss	1	1	2	2
Total periodic benefit (credit) cost	(7)	(52)	(21)	(154)
Non-U.S. | Defined Benefit Plans
Retirement and post-retirement benefit plans
Service cost	14	14	43	42
Interest cost	6	6	18	18
Expected return on plan assets	(9)	(10)	(28)	(30)
Amortization and deferrals:
Actuarial loss (gain)	8	7	24	21
Prior service benefit	(1)	(1)	(2)	(3)
Net periodic (credit) benefit cost	18	16	55	48
Curtailment gain	(9)	0	(9)	0
Settlement loss	0	0	0	0
Total periodic benefit (credit) cost	$ 9	$ 16	$ 46	$ 48