Segment Information - Schedule of Net Revenue by Segment and Business Unit (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Segment Reporting Information [Line Items]
Net revenue	$ 8,209	$ 8,005	$ 23,210	$ 25,046
Operating Segment
Segment Reporting Information [Line Items]
Net revenue	8,406	8,350	24,075	26,157
Elimination of intersegment net revenue and other
Segment Reporting Information [Line Items]
Net revenue	197	345	865	1,111
Enterprise Group
Segment Reporting Information [Line Items]
Net revenue	6,606	6,367	18,647	20,119
Enterprise Group | Operating Segment
Segment Reporting Information [Line Items]
Net revenue	6,791	6,615	19,359	20,956
Enterprise Group | Elimination of intersegment net revenue and other
Segment Reporting Information [Line Items]
Net revenue	185	248	712	837
Enterprise Group | Servers | Operating Segment
Segment Reporting Information [Line Items]
Net revenue	3,298	3,316	9,392	10,350
Enterprise Group | Technology Services | Operating Segment
Segment Reporting Information [Line Items]
Net revenue	1,947	1,933	5,861	5,937
Enterprise Group | Storage | Operating Segment
Segment Reporting Information [Line Items]
Net revenue	844	763	2,273	2,408
Enterprise Group | Networking | Operating Segment
Segment Reporting Information [Line Items]
Net revenue	702	603	1,833	2,261
Software
Segment Reporting Information [Line Items]
Net revenue	708	666	1,999	2,089
Software | Operating Segment
Segment Reporting Information [Line Items]
Net revenue	718	738	2,124	2,292
Software | Elimination of intersegment net revenue and other
Segment Reporting Information [Line Items]
Net revenue	10	72	125	203
Financial Services
Segment Reporting Information [Line Items]
Net revenue	895	787	2,564	2,305
Financial Services | Operating Segment
Segment Reporting Information [Line Items]
Net revenue	897	812	2,592	2,376
Financial Services | Elimination of intersegment net revenue and other
Segment Reporting Information [Line Items]
Net revenue	2	25	28	71
Corporate Investments
Segment Reporting Information [Line Items]
Net revenue	0	185	0	533
Corporate Investments | Operating Segment
Segment Reporting Information [Line Items]
Net revenue	0	185	0	533
Corporate Investments | Elimination of intersegment net revenue and other
Segment Reporting Information [Line Items]
Net revenue	$ 0	$ 0	$ 0	$ 0