PENSION AND OTHER POSTRETIREMENT BENEFITS - Components of Benefit Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014
Change in Accounting Method Accounted for as Change in Estimate
Net Periodic Cost
Decrease in service and interest costs compared to previous method	$ 175
Pensions
Net Periodic Cost
Service cost	254	$ 282	$ 244
Interest cost	391	474	480
Expected return on plan assets	(775)	(769)	(776)
Amortization of actuarial (gain) loss	211	223	177
Amortization of prior service (credit) cost	16	25	25
Other postemployment benefits	2	1	5
Settlements/curtailments	11	11	9
Net cost	$ 110	$ 247	$ 164
Weighted-Average Assumptions
Discount rates - service cost (as a percent)	4.30%	4.00%	4.50%
Discount rates - interest cost (as a percent)	3.40%	4.00%	4.50%
Rate of compensation increase (as a percent)	3.80%	3.80%	3.80%
Expected long-term rates of return (as a percent)	7.30%	7.30%	7.50%
Pensions | Change in Accounting Method Accounted for as Change in Estimate
Weighted-Average Assumptions
Discount rates - single weighted-average (as a percent)	4.10%
Health Care and Life Insurance
Net Periodic Cost
Service cost	$ 38	$ 46	$ 44
Interest cost	204	259	267
Expected return on plan assets	(35)	(55)	(72)
Amortization of actuarial (gain) loss	73	91	33
Amortization of prior service (credit) cost	(78)	(77)	(3)
Settlements/curtailments		1	(1)
Net cost	$ 202	$ 265	$ 268
Weighted-Average Assumptions
Discount rates - service cost (as a percent)	5.00%	4.20%	4.70%
Discount rates - interest cost (as a percent)	3.50%	4.20%	4.70%
Expected long-term rates of return (as a percent)	6.60%	7.00%	7.20%
Health Care and Life Insurance | Change in Accounting Method Accounted for as Change in Estimate
Weighted-Average Assumptions
Discount rates - single weighted-average (as a percent)	4.30%