Leases - Supplemental Cash Flow Information (Details) $ in Millions	12 Months Ended
	Oct. 31, 2020 USD ($)
Leases [Abstract]
Cash paid for amount included in the measurement of lease liabilities	$ 236
Right-of-use assets obtained in exchange of lease liabilities	$ 226
Weighted-average remaining lease term in years	6 years
Weighted-average discount rate	3.10%