Debt - Schedule of Debt Issuances (Details) € in Millions, $ in Millions	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2021 EUR (€)	Mar. 31, 2021 USD ($)	Mar. 31, 2021 EUR (€)
4.298% Notes due August 22, 2032
Debt Instrument [Line Items]
Interest rate	4.298%
Debt instrument, face amount	$ 500
1.957% Notes due February 11, 2031
Debt Instrument [Line Items]
Interest rate	1.957%			1.957%	1.957%
Debt instrument, face amount				$ 1,000
Notes 3.125% due November 8, 2021
Debt Instrument [Line Items]
Interest rate				3.125%	3.125%
0.000% Notes due August 13, 2023
Debt Instrument [Line Items]
Interest rate	0.00%	0.00%	0.00%
0.000% Notes due August 13, 2023 | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €			€ 400
0.000% Notes due August 13, 2023 | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount		$ 470
0.034% Notes due August 13, 2025
Debt Instrument [Line Items]
Interest rate	0.034%	0.034%	0.034%
0.034% Notes due August 13, 2025 | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €			€ 500
0.034% Notes due August 13, 2025 | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount		$ 587
0.334% Notes due August 13, 2028
Debt Instrument [Line Items]
Interest rate	0.334%	0.334%	0.334%
0.334% Notes due August 13, 2028 | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €			€ 900
0.334% Notes due August 13, 2028 | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,055
1.336% Notes due August 13, 2041
Debt Instrument [Line Items]
Interest rate	1.336%	1.336%	1.336%
1.336% Notes due August 13, 2041 | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €			€ 900
1.336% Notes due August 13, 2041 | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,055
1.213% Notes due February 12, 2036
Debt Instrument [Line Items]
Interest rate				1.213%	1.213%
1.213% Notes due February 12, 2036 | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €					€ 600
1.213% Notes due February 12, 2036 | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount				$ 728
Notes 0.174% due June 4, 2021
Debt Instrument [Line Items]
Interest rate				0.174%	0.174%