Debt - Schedule (Parenthetical) (Details)	Mar. 31, 2022 CAD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2022 EUR (€)
CAD 500 million 2.84% notes due July 2023
Debt Instrument [Line Items]
Debt instrument, face amount	$ 500,000,000
Debt Instrument, interest rate	2.84%	2.84%	2.84%
CAD 500 million 3.44% notes due July 2026
Debt Instrument [Line Items]
Debt instrument, face amount	$ 500,000,000
Debt Instrument, interest rate	3.44%	3.44%	3.44%
$500 million 3.5% notes due May 2022
Debt Instrument [Line Items]
Debt instrument, face amount		$ 500,000,000
Debt Instrument, interest rate	3.50%	3.50%	3.50%
$2.0 billion 3.0% notes due July 2026
Debt Instrument [Line Items]
Debt instrument, face amount		$ 2,000,000,000.0
Debt Instrument, interest rate	3.00%	3.00%	3.00%
$1.1 billion 5.0% notes due May 2042
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,100,000,000
Debt Instrument, interest rate	5.00%	5.00%	5.00%
$1.8 billion 4.2% notes due July 2046
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,800,000,000
Debt Instrument, interest rate	4.20%	4.20%	4.20%
EUR 800 million 1.25% notes due July 2024
Debt Instrument [Line Items]
Debt instrument, face amount | €			€ 800,000,000
Debt Instrument, interest rate	1.25%	1.25%	1.25%