Goodwill - Schedule of Allocation and Changes in the Carrying Amount of Goodwill (Details)	3 Months Ended
	Jan. 31, 2019 USD ($)
Goodwill [Roll Forward]
Goodwill beginning balance	$ 17,537,000,000
Goodwill acquired during the period	49,000,000
Goodwill adjustments	2,000,000
Goodwill ending balance	17,588,000,000
Hybrid IT
Goodwill [Roll Forward]
Goodwill beginning balance	15,479,000,000
Goodwill acquired during the period	49,000,000
Goodwill adjustments	2,000,000
Goodwill ending balance	15,530,000,000
Intelligent Edge
Goodwill [Roll Forward]
Goodwill beginning balance	1,914,000,000
Goodwill acquired during the period	0
Goodwill adjustments	0
Goodwill ending balance	1,914,000,000
Financial Services
Goodwill [Roll Forward]
Goodwill beginning balance	144,000,000
Goodwill acquired during the period	0
Goodwill adjustments	0
Goodwill ending balance	144,000,000
Corporate Investments
Goodwill [Roll Forward]
Goodwill beginning balance	88,000,000
Goodwill ending balance	$ 0