Goodwill and Intangible Assets (Details) - USD ($)	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Goodwill
Balance at beginning of period	$ 17,537,000,000	$ 17,516,000,000
Goodwill acquired during the period	767,000,000	104,000,000
Impairment of goodwill	0	(88,000,000)	$ 0
Changes due to foreign currency		(1,000,000)
Goodwill adjustments	2,000,000	6,000,000
Balance at end of period	18,306,000,000	17,537,000,000	17,516,000,000
Corporate Investments
Goodwill
Balance at beginning of period	0	88,000,000
Goodwill acquired during the period	0	0
Impairment of goodwill		(88,000,000)
Changes due to foreign currency		0
Goodwill adjustments	0	0
Balance at end of period	0	0	88,000,000
Hybrid IT
Goodwill
Balance at beginning of period	15,479,000,000	15,373,000,000
Goodwill acquired during the period	767,000,000	101,000,000
Impairment of goodwill		0
Changes due to foreign currency		(1,000,000)
Goodwill adjustments	2,000,000	6,000,000
Balance at end of period	16,248,000,000	15,479,000,000	15,373,000,000
Intelligent Edge
Goodwill
Balance at beginning of period	1,914,000,000	1,911,000,000
Goodwill acquired during the period	0	3,000,000
Changes due to foreign currency		0
Goodwill adjustments	0	0
Balance at end of period	1,914,000,000	1,914,000,000	1,911,000,000
Financial Services
Goodwill
Balance at beginning of period	144,000,000	144,000,000
Goodwill acquired during the period	0	0
Changes due to foreign currency		0
Goodwill adjustments	0	0
Balance at end of period	$ 144,000,000	$ 144,000,000	$ 144,000,000