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Debt - Schedule of Debt Instruments (Details) - USD ($) $ in Millions	Jul. 31, 2020	Apr. 30, 2020	Apr. 27, 2020	Oct. 31, 2019
Debt Instrument [Line Items]
Long-term Debt and Lease Obligation	$ 4,694			$ 4,317
Senior Notes \| 9.5% Senior Secured Notes, due 2025
Debt Instrument [Line Items]
Interest rate			9.50%
Debt issuance costs		$ 12	$ 12
Financial Services Operations
Debt Instrument [Line Items]
Long-term Debt and Lease Obligation, Including Current Maturities	2,027			2,256
Long-term Debt and Lease Obligation, Current	792			839
Long-term Debt and Lease Obligation	1,235			1,417
Financial Services Operations \| Secured Debt [Member]
Debt Instrument [Line Items]
Long-term Debt	1,008			991
Debt Issuance Costs, Net		2		4
Financial Services Operations \| Line of Credit [Member]
Debt Instrument [Line Items]
Long-term Debt	914			1,059
Debt Issuance Costs, Net		1		1
Financial Services Operations \| Commercial Paper [Member]
Debt Instrument [Line Items]
Long-term Debt				84
Commercial Paper	0
Financial Services Operations \| Borrowings Secured By Operating and Finance Leases [Member]
Debt Instrument [Line Items]
Long-term Debt	105			122
Manufacturing Operations [Member]
Debt Instrument [Line Items]
Long-term Debt and Lease Obligation, Including Current Maturities	3,532			2,932
Long-term Debt and Lease Obligation, Current	73			32
Long-term Debt and Lease Obligation	3,459			2,900
Manufacturing Operations [Member] \| Line of Credit [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		5		6
Long-term Debt	1,547			1,556
Debt Issuance Costs, Net		9		10
Manufacturing Operations [Member] \| Notes Payable to Banks [Member] \| 6.625% Senior Notes, due 2026
Debt Instrument [Line Items]
Long-term Debt	1,087			1,085
Debt Issuance Costs, Net		$ 14		15
Manufacturing Operations [Member] \| Senior Notes
Debt Instrument [Line Items]
Long-term Debt	589
Manufacturing Operations [Member] \| Convertible Subordinated Debt [Member] \| Four Point Five Zero Senior Subordinated Convertible Notes [Member]
Debt Instrument [Line Items]
Interest rate		4.50%
Manufacturing Operations [Member] \| Convertible Subordinated Debt [Member] \| Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member]
Debt Instrument [Line Items]
Interest rate		4.75%
Manufacturing Operations [Member] \| Tax Exempt Bond [Member]
Debt Instrument [Line Items]
Interest rate		6.75%
Long-term Debt	220			220
Debt Issuance Costs, Net		$ 5		5
Manufacturing Operations [Member] \| Financed lease obligations [Member]
Debt Instrument [Line Items]
Long-term Debt	48			60
Manufacturing Operations [Member] \| Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 41			$ 11