Segment Information (Details 4) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014
Segment Reporting Information
Net revenue	$ (50,123)	$ (52,107)	$ (55,123)
Operating segments
Segment Reporting Information
Net revenue	(52,479)	(54,558)	(57,560)
Eliminations of inter-segment net revenue and other
Segment Reporting Information
Net revenue	(2,356)	(2,451)	(2,437)
Enterprise Group
Segment Reporting Information
Net revenue	(26,017)	(26,668)	(26,812)
Enterprise Group | Operating segments
Segment Reporting Information
Net revenue	(27,219)	(27,907)	(27,727)
Enterprise Group | Operating segments | Servers
Segment Reporting Information
Net revenue	(14,019)	(14,219)	(13,401)
Enterprise Group | Operating segments | Technology Services
Segment Reporting Information
Net revenue	(7,160)	(7,662)	(8,383)
Enterprise Group | Operating segments | Storage
Segment Reporting Information
Net revenue	(3,065)	(3,180)	(3,315)
Enterprise Group | Operating segments | Networking
Segment Reporting Information
Net revenue	(2,975)	(2,846)	(2,628)
Enterprise Group | Eliminations of inter-segment net revenue and other
Segment Reporting Information
Net revenue	(1,202)	(1,239)	(915)
Enterprise Services
Segment Reporting Information
Net revenue	(18,094)	(19,010)	(21,297)
Enterprise Services | Operating segments
Segment Reporting Information
Net revenue	(18,872)	(19,806)	(22,398)
Enterprise Services | Operating segments | Infrastructure Technology Outsourcing
Segment Reporting Information
Net revenue	(11,425)	(12,107)	(14,038)
Enterprise Services | Operating segments | Application and Business Services
Segment Reporting Information
Net revenue	(7,447)	(7,699)	(8,360)
Enterprise Services | Eliminations of inter-segment net revenue and other
Segment Reporting Information
Net revenue	(778)	(796)	(1,101)
Software
Segment Reporting Information
Net revenue	(2,912)	(3,308)	(3,609)
Software | Operating segments
Segment Reporting Information
Net revenue	(3,195)	(3,622)	(3,933)
Software | Eliminations of inter-segment net revenue and other
Segment Reporting Information
Net revenue	(283)	(314)	(324)
Financial Services
Segment Reporting Information
Net revenue	(3,097)	(3,114)	(3,401)
Financial Services | Operating segments
Segment Reporting Information
Net revenue	(3,190)	(3,216)	(3,498)
Financial Services | Eliminations of inter-segment net revenue and other
Segment Reporting Information
Net revenue	(93)	(102)	(97)
Corporate Investments
Segment Reporting Information
Net revenue	(3)	(7)	(4)
Corporate Investments | Operating segments
Segment Reporting Information
Net revenue	(3)	(7)	(4)
Corporate Investments | Eliminations of inter-segment net revenue and other
Segment Reporting Information
Net revenue	$ 0	$ 0	$ 0