Financing Receivables and Operating Leases - Gross Financing Receivables and Related Allowance Evaluated for Loss (Details) - USD ($) $ in Millions	Jul. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Leases [Abstract]
Gross financing receivables collectively evaluated for loss	$ 8,120	$ 7,917
Gross financing receivables individually evaluated for loss(1)	446	339
Financing receivables, gross	8,566	8,256
Allowance for financing receivables collectively evaluated for loss	84	78
Allowance for financing receivables individually evaluated for loss	49	42
Total	$ 133	$ 120	$ 86

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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Amount, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

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