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Debt - Long-term Debt (Details) € in Millions, $ in Millions	Sep. 30, 2021 USD ($)	Sep. 30, 2021 EUR (€)	Aug. 31, 2021	Aug. 16, 2021 EUR (€)	Apr. 30, 2021	Apr. 15, 2021	Mar. 08, 2021	Jan. 20, 2021	Nov. 02, 2020 USD ($)	Sep. 30, 2020 USD ($)	Aug. 12, 2020 USD ($)	Jun. 30, 2020	Jun. 29, 2020 USD ($)	Jun. 29, 2020 EUR (€)	Sep. 30, 2019
Debt Instrument [Line Items]
Total long-term debt, including the current portion	$ 3,383									$ 3,127
Issuance premium less unamortized discount and unamortized deferred financing costs	(37)									(23)
Total long-term debt, including the current portion, net	$ 3,346									$ 3,104
3.625% Senior Secured Notes
Debt Instrument [Line Items]
Interest rate	3.625%	3.625%								3.625%					3.625%
2.250% Senior Secured Notes
Debt Instrument [Line Items]
Interest rate	2.25%	2.25%								2.25%					2.25%
5.500% Senior Notes due 2026
Debt Instrument [Line Items]
Interest rate	5.50%	5.50%								5.50%					5.50%
Acquisition Corp. \| Senior Term Loan Facility due 2028
Debt Instrument [Line Items]
Total long-term debt, including the current portion	$ 1,145									$ 820
Acquisition Corp. \| 3.625% Senior Secured Notes
Debt Instrument [Line Items]
Interest rate	3.625%	3.625%	3.625%	3.625%
Face or principal amount of debt instrument \| €		€ 445
Total long-term debt, including the current portion	$ 0									518
Acquisition Corp. \| 2.750% Senior Secured Notes due 2028
Debt Instrument [Line Items]
Interest rate	2.75%	2.75%						2.75%				2.75%	2.75%	2.75%
Face or principal amount of debt instrument \| €		€ 325												€ 325
Total long-term debt, including the current portion	$ 381									379
Acquisition Corp. \| 3.875% Senior Secured Notes due 2030
Debt Instrument [Line Items]
Interest rate	3.875%	3.875%						3.875%				3.875%	3.875%	3.875%
Face or principal amount of debt instrument													$ 535
Total long-term debt, including the current portion	$ 535									535
Acquisition Corp. \| 2.250% Senior Secured Notes
Debt Instrument [Line Items]
Interest rate	2.25%	2.25%		2.25%				2.25%
Face or principal amount of debt instrument \| €		€ 445		€ 445
Total long-term debt, including the current portion	$ 522									0
Acquisition Corp. \| 3.000% Senior Secured Notes due 2031
Debt Instrument [Line Items]
Interest rate	3.00%	3.00%						3.00%	3.00%		3.00%
Face or principal amount of debt instrument									$ 250		$ 550
Total long-term debt, including the current portion	$ 800									550
Acquisition Corp. \| 5.500% Senior Notes due 2026
Debt Instrument [Line Items]
Interest rate	5.50%	5.50%			5.50%	5.50%	5.50%
Total long-term debt, including the current portion	$ 0									325
Acquisition Corp. \| Revolving Credit Facility
Debt Instrument [Line Items]
Total long-term debt, including the current portion	0									0
Line of credit facility, current borrowing capacity	300									300			$ 300
Letters of credit outstanding	7									10
Revolving credit facility outstanding	$ 0									$ 0