Debt - Schedule of Debt Issuances (Details) € in Millions	Sep. 30, 2021 USD ($)	Sep. 30, 2021 EUR (€)	Mar. 31, 2021 USD ($)	Mar. 31, 2021 EUR (€)	Jun. 30, 2020 USD ($)
Notes 1.957% due February 11, 2031
Debt Instrument [Line Items]
Interest rate	1.957%	1.957%
Debt instrument, face amount			$ 1,000,000,000
Notes 3.125% due November 8, 2021
Debt Instrument [Line Items]
Interest rate	3.125%	3.125%
Notes 2.823% due May 20, 2030
Debt Instrument [Line Items]
Interest rate	2.823%	2.823%
Debt instrument, face amount					$ 750,000,000
Notes 2.404% due June 5, 2020 [Member]
Debt Instrument [Line Items]
Interest rate	2.404%	2.404%
Notes 3.250% due November 12, 2020 [Member]
Debt Instrument [Line Items]
Interest rate	3.25%	3.25%
Notes 3.794% due May 20, 2050
Debt Instrument [Line Items]
Interest rate	3.794%	3.794%
Debt instrument, face amount					$ 750,000,000
Notes 0.000% due August 13, 2023 [Member]
Debt Instrument [Line Items]
Interest rate	0.00%	0.00%
Notes 0.000% due August 13, 2023 [Member] | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €		€ 400
Notes 0.000% due August 13, 2023 [Member] | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount	$ 470,000,000
Notes 0.034% due August 13, 2025 [Member]
Debt Instrument [Line Items]
Interest rate	0.034%	0.034%
Notes 0.034% due August 13, 2025 [Member] | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €		€ 500
Notes 0.034% due August 13, 2025 [Member] | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount	$ 587,000,000
Notes 0.334% due August 13, 2028
Debt Instrument [Line Items]
Interest rate	0.334%	0.334%
Notes 0.334% due August 13, 2028 | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €		€ 900
Notes 0.334% due August 13, 2028 | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount	$ 1,055,000,000
Notes 1.336 due August 13, 2041
Debt Instrument [Line Items]
Interest rate	1.336%	1.336%
Notes 1.336 due August 13, 2041 | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €		€ 900
Notes 1.336 due August 13, 2041 | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount	$ 1,055,000,000
Notes 1.213% due February 12, 2036 [Member]
Debt Instrument [Line Items]
Interest rate	1.213%	1.213%
Notes 1.213% due February 12, 2036 [Member] | Euro Member Countries, Euro
Debt Instrument [Line Items]
Debt instrument, face amount | €				€ 600
Notes 1.213% due February 12, 2036 [Member] | United States of America, Dollars
Debt Instrument [Line Items]
Debt instrument, face amount			$ 728,000,000
Notes 0.174% due June 4, 2021 [Member]
Debt Instrument [Line Items]
Interest rate	0.174%	0.174%