Segment Information - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2026	Jul. 31, 2025	Jul. 31, 2026	Jul. 31, 2025
Earnings (Loss) Before Taxes:
Total consolidated net revenue	$ 12,213	$ 9,136	$ 32,192	$ 24,617
Networking
Earnings (Loss) Before Taxes:
Total consolidated net revenue	2,893	1,654	8,289	3,814
Campus & Branch
Earnings (Loss) Before Taxes:
Total consolidated net revenue	1,442	1,101	3,991	2,845
Data Center Networking
Earnings (Loss) Before Taxes:
Total consolidated net revenue	382	180	1,146	368
Security
Earnings (Loss) Before Taxes:
Total consolidated net revenue	281	160	809	386
Routing
Earnings (Loss) Before Taxes:
Total consolidated net revenue	788	213	2,343	215
Cloud & AI
Earnings (Loss) Before Taxes:
Total consolidated net revenue	9,042	7,212	23,083	19,994
Server
Earnings (Loss) Before Taxes:
Total consolidated net revenue	6,766	5,000	16,452	13,457
Storage
Earnings (Loss) Before Taxes:
Total consolidated net revenue	1,291	1,171	3,527	3,374
Financial Services
Earnings (Loss) Before Taxes:
Total consolidated net revenue	883	886	2,663	2,615
Other
Earnings (Loss) Before Taxes:
Total consolidated net revenue	102	155	441	548
Corporate Investments and Other
Earnings (Loss) Before Taxes:
Total consolidated net revenue	$ 278	$ 270	$ 820	$ 809