Retirement and Post-Retirement Benefit Plans (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Jan. 31, 2017	Jan. 31, 2016	Oct. 31, 2016
Defined benefit plans
Pension expense adjustment		$ 65	$ 29
Defined benefit plan settlement charges and remeasurement benefit	[1]	6	0
Employer Contributions and Funding Policy
Transfer threshold		570
Non-U.S. Defined Benefit Plans
Net benefit (credit) cost
Service cost		55	64
Interest cost		91	141
Expected return on plan assets		(181)	(254)
Amortization and deferrals:
Actuarial loss (gain)		104	79
Prior service benefit		(6)	(6)
Net periodic benefit cost		63	24
Settlement loss		0	4
Special termination benefits		1	0
Net benefit cost		64	28
Employer Contributions and Funding Policy
Expected contribution to defined benefit plans				$ 348
Contributions to benefit plans		1,943
Expected additional contribution to benefit plans as a result of impact of foreign currency		290
U.S. non-qualified plan participants
Employer Contributions and Funding Policy
Expected contribution to defined benefit plans				2
Expected additional contribution to benefit plans as a result of impact of foreign currency		2
Post-Retirement Benefit Plans
Net benefit (credit) cost
Service cost		1	1
Interest cost		1	2
Expected return on plan assets		0	(1)
Amortization and deferrals:
Actuarial loss (gain)		(1)	(1)
Prior service benefit		0	0
Net periodic benefit cost		1	1
Settlement loss		0	0
Special termination benefits		0	0
Net benefit cost		1	$ 1
Employer Contributions and Funding Policy
Expected contribution to defined benefit plans		1		$ 3
Expected additional contribution to benefit plans as a result of impact of foreign currency		2
Minimum | Non-U.S. Defined Benefit Plans
Employer Contributions and Funding Policy
Estimated funding		2,000
Maximum | Non-U.S. Defined Benefit Plans
Employer Contributions and Funding Policy
Estimated funding		3,000
Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff
Defined benefit plans
Pension expense adjustment		33
Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff | Non-U.S. Defined Benefit Plans
Employer Contributions and Funding Policy
Contributions to benefit plans		$ 1,885

[1] Represents adjustment to net periodic pension cost resulting from remeasurements of certain Hewlett Packard Enterprise pension plans due to plan separations in anticipation of the spin-off and merger of Everett SpinCo, Inc. with Computer Sciences Corporation.