PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended		12 Months Ended
	Nov. 01, 2015	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015	Oct. 31, 2016
Forecasted
Net Periodic Cost
Decrease in service and interest costs compared to previous method						$ 175
Pensions
Net Periodic Cost
Service cost		$ 62	$ 69	$ 126	$ 142
Interest cost		97	119	195	238
Expected return on plan assets		(194)	(192)	(387)	(385)
Amortization of actuarial (gain) loss		52	55	104	110
Amortization of prior service (credit) cost		4	6	8	12
Settlements/curtailments		2		9	1
Net cost		23	57	55	118
Defined benefit plan employer contributions				48
Defined benefit plan employer contributions expected for the remainder of the fiscal year				31
Service cost discount rates (as a percent)	4.30%
Interest cost discount rates (as a percent)	3.40%
Discount rates (as a percent)	4.10%
Health Care and Life Insurance
Net Periodic Cost
Service cost		10	12	19	23
Interest cost		51	64	102	129
Expected return on plan assets		(9)	(14)	(18)	(28)
Amortization of actuarial (gain) loss		18	23	37	46
Amortization of prior service (credit) cost		(20)	(19)	(39)	(38)
Net cost		$ 50	$ 66	101	$ 132
Defined benefit plan employer contributions				23
Defined benefit plan employer contributions expected for the remainder of the fiscal year				$ 3
Service cost discount rates (as a percent)	5.00%
Interest cost discount rates (as a percent)	3.50%
Discount rates (as a percent)	4.30%