Borrowings - Narrative (Details) - USD ($)		1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2023	Jul. 31, 2023	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2023	Jul. 31, 2022
Line of Credit Facility [Line Items]
Net gain on debt extinguishment			$ 115,000,000	$ 0	$ 107,000,000	$ 0
Commercial Paper
Line of Credit Facility [Line Items]
Maximum borrowing capacity under credit facility		$ 6,000,000,000	6,000,000,000		6,000,000,000
Revolving credit facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity under credit facility		5,000,000,000	5,000,000,000		5,000,000,000
Credit facilities
Line of Credit Facility [Line Items]
Available borrowing resources		1,200,000,000	1,200,000,000		1,200,000,000
U.S. Dollar Global Notes Due June 2026, June 2030 And April 2032
Line of Credit Facility [Line Items]
Repurchased amount		1,150,000,000	$ 1,150,000,000		$ 1,150,000,000
Net gain on debt extinguishment		$ 115,000,000
$1,000 issued at discount to par at a price of 99.808% at 1.45%, due June 2026
Line of Credit Facility [Line Items]
Interest rate (percent)		1.45%	1.45%		1.45%
$850 issued at discount to par at a price of 99.790% at 3.4%, due June 2030
Line of Credit Facility [Line Items]
Interest rate (percent)		3.40%	3.40%		3.40%
$1,000 issued at discount to par at a price of 99.966% at 4.20%, due April 2032
Line of Credit Facility [Line Items]
Interest rate (percent)		4.20%	4.20%		4.20%
364-Day Revolving Credit Facility | Revolving credit facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity under credit facility	$ 1,000,000,000
Revolving credit facility, term	364 days