Retirement and Post-Retirement Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Apr. 30, 2014	Jul. 31, 2015	Jul. 31, 2014	Oct. 31, 2014
Employer Contributions and Funding Policy
Reduction in expected contributions			$ 52
Lump sum payments to participants	$ 114			$ 114
U.S. Defined Benefit Plans
Net benefit (credit) cost
Interest cost	141	$ 142		427	$ 426
Expected return on plan assets	(197)	(203)		(630)	(608)
Amortization and deferrals:
Actuarial loss (gain)	13	4		39	12
Net periodic benefit (credit) cost	(43)	(57)		(164)	(170)
Settlement loss	96	1		96	1
Net benefit cost (credit)	$ 53	(56)		(68)	(169)
Employer Contributions and Funding Policy
Percentage of eligible participants who elected to receive benefits	50.00%
Lump sum payments to participants	$ 827
Net improvement in net funded status after re-measurement				107
Re-measurement resulting in additional benefit cost				45
Re-measurement resulting in additional benefit cost for the current period	18			18
Non-U.S. Defined Benefit Plans
Net benefit (credit) cost
Service cost	82	78		249	233
Interest cost	155	187		471	555
Expected return on plan assets	(292)	(290)		(884)	(858)
Amortization and deferrals:
Actuarial loss (gain)	107	81		323	239
Prior service benefit	(5)	(6)		(15)	(18)
Net periodic benefit (credit) cost	47	50		144	151
Curtailment gain					(5)
Settlement loss		2		3	4
Special termination benefits	9	5		22	33
Net benefit cost (credit)	56	57		169	183
Employer Contributions and Funding Policy
Expected contribution to benefit plans as of balance sheet date						$ 641
Contributions to benefit plans				575
Expected additional contribution to benefit plans as of balance sheet date				66
U.S. non-qualified plan participants
Employer Contributions and Funding Policy
Expected contribution to benefit plans as of balance sheet date						32
Contributions to benefit plans				22
Expected additional contribution to benefit plans as of balance sheet date				10
Post-Retirement Benefit Plans
Net benefit (credit) cost
Service cost	1	1		3	3
Interest cost	7	8		21	24
Expected return on plan assets	(10)	(9)		(28)	(26)
Amortization and deferrals:
Actuarial loss (gain)	(2)	(2)		(8)	(7)
Prior service benefit	(5)	(10)		(15)	(30)
Net periodic benefit (credit) cost	(9)	(12)		(27)	(36)
Special termination benefits	1			1	(11)
Net benefit cost (credit)	$ (8)	$ (12)		(26)	$ (47)
Employer Contributions and Funding Policy
Expected contribution to benefit plans as of balance sheet date						$ 43
Contributions to benefit plans				29
Expected additional contribution to benefit plans as of balance sheet date				$ 14