Segment Information - Subsegments (Details) - USD ($) $ in Millions	3 Months Ended
	Jan. 31, 2017	Jan. 31, 2016
Segment Reporting Information
Net revenue	$ 11,407	$ 12,724
Operating segments
Segment Reporting Information
Net revenue	11,906	13,294
Elimination of intersegment net revenue and other
Segment Reporting Information
Net revenue	499	570
Enterprise Group
Segment Reporting Information
Net revenue	6,097	6,882
Enterprise Group | Operating segments
Segment Reporting Information
Net revenue	6,325	7,182
Enterprise Group | Operating segments | Servers
Segment Reporting Information
Net revenue	3,103	3,536
Enterprise Group | Operating segments | Technology Services
Segment Reporting Information
Net revenue	1,943	1,985
Enterprise Group | Operating segments | Storage
Segment Reporting Information
Net revenue	730	837
Enterprise Group | Operating segments | Networking
Segment Reporting Information
Net revenue	549	824
Enterprise Group | Elimination of intersegment net revenue and other
Segment Reporting Information
Net revenue	228	300
Enterprise Services
Segment Reporting Information
Net revenue	3,852	4,367
Enterprise Services | Operating segments
Segment Reporting Information
Net revenue	4,037	4,555
Enterprise Services | Operating segments | Infrastructure Technology Outsourcing
Segment Reporting Information
Net revenue	2,637	2,874
Enterprise Services | Operating segments | Application and Business Services
Segment Reporting Information
Net revenue	1,400	1,681
Enterprise Services | Elimination of intersegment net revenue and other
Segment Reporting Information
Net revenue	185	188
Software
Segment Reporting Information
Net revenue	654	720
Software | Operating segments
Segment Reporting Information
Net revenue	721	780
Software | Elimination of intersegment net revenue and other
Segment Reporting Information
Net revenue	67	60
Financial Services
Segment Reporting Information
Net revenue	804	754
Financial Services | Operating segments
Segment Reporting Information
Net revenue	823	776
Financial Services | Elimination of intersegment net revenue and other
Segment Reporting Information
Net revenue	19	22
Corporate Investments
Segment Reporting Information
Net revenue	0	1
Corporate Investments | Operating segments
Segment Reporting Information
Net revenue	0	1
Corporate Investments | Elimination of intersegment net revenue and other
Segment Reporting Information
Net revenue	$ 0	$ 0