Borrowings (Details 2)	1 Months Ended	12 Months Ended
	Sep. 30, 2019 USD ($) tranche	Oct. 31, 2019 USD ($)	Oct. 31, 2018 USD ($)	Oct. 31, 2017 USD ($)
Long-term debt
Total long-term debt		$ 9,395,000,000	$ 10,136,000,000
Fair value adjustment related to hedged debt		61,000,000	(353,000,000)
Unamortized debt issuance costs		(47,000,000)	(42,000,000)
Less: current portion		(3,441,000,000)	(1,196,000,000)
Interest expense on borrowings recognized in Combined Statements of Earnings
Financing interest		297,000,000	278,000,000	$ 265,000,000
Interest expense		311,000,000	353,000,000	334,000,000
Total interest expense		$ 608,000,000	$ 631,000,000	$ 599,000,000
Weighted average interest rate (as a percent)		4.10%	2.20%
$1,100 issued at discount to par at a price of 99.994% in September 2017 at 2.10%, paid October 4, 2019, interest payable semi-annually on April 4 and October 4 of each year
Long-term debt
Total long-term debt		$ 0	$ 1,100,000,000
Face amount of debt instrument			$ 1,100,000,000
Discount to par (as a percent)			99.994%
Interest rate			2.10%
$3,000 issued at discount to par at a price of 99.972% in October 2015 at 3.6%, due October 15, 2020, interest payable semi-annually on April 15 and October 15 of each year
Long-term debt
Total long-term debt		3,000,000,000	$ 3,000,000,000
Face amount of debt instrument		$ 3,000,000,000
Discount to par (as a percent)		99.972%
Interest rate		3.60%
$500 issued at discount to par at a price of 99.861% in September 2018 at 3.5%, due October 5, 2021, interest payable semi-annually on April 5 and October 5 of each year
Long-term debt
Total long-term debt		$ 500,000,000	499,000,000
Face amount of debt instrument		$ 500,000,000
Discount to par (as a percent)		99.861%
Interest rate		3.50%
$800 issued at par in September 2018 at three-month USD LIBOR plus 0.72% due October 5, 2021, interest payable semi-annually on April 5 and October 5 of each year
Long-term debt
Total long-term debt		$ 800,000,000	800,000,000
$800 issued at par in September 2018 at three-month USD LIBOR plus 0.72% due October 5, 2021, interest payable semi-annually on April 5 and October 5 of each year | LIBOR
Long-term debt
Face amount of debt instrument		$ 800,000,000
Interest rate		0.72%
$500 issued at par in September 2019 at three-month USD LIBOR plus 0.68% due March 12, 2021, interest payable quarterly on March 12, June 12, September 12 and December 12 of each year
Long-term debt
Total long-term debt		$ 500,000,000	0
$1,350 issued at discount to par at a price of 99.802% in October 2015 at 4.4%, due October 15, 2022, interest payable semi-annually on April 15 and October 15 of each year
Long-term debt
Total long-term debt		1,349,000,000	1,348,000,000
Face amount of debt instrument		$ 1,350,000,000
Discount to par (as a percent)		99.802%
Interest rate		4.40%
$1,000 issued at discount to par at a price of 99.979% in September 2019 at 2.25%, due April 1, 2023, interest payable semi-annually on April 1 and October 1 of each year
Long-term debt
Total long-term debt		$ 1,000,000,000	0
Face amount of debt instrument		$ 1,000,000,000
Discount to par (as a percent)		99.979%
Interest rate		2.25%
$2,500 issued at discount to par at a price of 99.725% in October 2015 at 4.9%, due October 15, 2025, interest payable semi-annually on April 15 and October 15 of each year
Long-term debt
Total long-term debt		$ 2,495,000,000	2,495,000,000
Face amount of debt instrument		$ 2,500,000,000
Discount to par (as a percent)		99.725%
Interest rate		4.90%
$750 issued at discount to par at a price of 99.942% in October 2015 at 6.2%, due October 15, 2035, interest payable semi-annually on April 15 and October 15 of each year
Long-term debt
Total long-term debt		$ 750,000,000	750,000,000
Face amount of debt instrument		$ 750,000,000
Discount to par (as a percent)		99.942%
Interest rate		6.20%
$1,500 issued at discount to par at a price of 99.932% in October 2015 at 6.35%, due October 15, 2045, interest payable semi-annually on April 15 and October 15 of each year
Long-term debt
Total long-term debt		$ 1,499,000,000	1,499,000,000
Face amount of debt instrument		$ 1,500,000,000
Discount to par (as a percent)		99.932%
Interest rate		6.35%
Other, including capital lease obligations, at 0.00%-5.52%, due in calendar years 2019-2030(1)
Long-term debt
Other, including capital lease obligations, at 0.00%-5.52%, due in calendar years 2019-2030(1)		$ 166,000,000	236,000,000
Other, including capital lease obligations, at 0.00%-5.52%, due in calendar years 2019-2030(1) | Financial Services
Long-term debt
Other, including capital lease obligations		$ 80,000,000	131,000,000
Other, including capital lease obligations, at 0.00%-5.52%, due in calendar years 2019-2030(1) | Minimum
Long-term debt
Interest rate		0.00%
Other, including capital lease obligations, at 0.00%-5.52%, due in calendar years 2019-2030(1) | Maximum
Long-term debt
Interest rate		5.52%
Asset backed securities
Long-term debt
Secured Debt		$ 763,000,000	$ 0
Face amount of debt instrument	$ 763,000,000
Discount to par (as a percent)	99.99%
Number of tranches | tranche	6
Interest expense on borrowings recognized in Combined Statements of Earnings
Weighted average interest rate (as a percent)	2.31%