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Debt - Schedule (Details)	Jun. 30, 2020 USD ($)	Jun. 30, 2020 CAD ($)	Jun. 30, 2020 EUR (€)	Dec. 31, 2019 USD ($)	May 03, 2012 USD ($)
Debt Instrument [Line Items]
Less: unamortized debt discounts and debt issuance costs	$ (53,100,000)			$ (56,700,000)
Total long-term debt (including current portion)	8,477,100,000			9,030,800,000
Current portion of long-term debt	(403,400,000)			(921,300,000)
Long-term debt	8,073,700,000			8,109,500,000
Commercial paper programs	199,900,000			0
Other short-term borrowings	9,700,000			6,900,000
Current portion of long-term debt and short-term borrowings	$ 613,000,000.0			928,200,000
CAD 500 million 2.75% notes due September 2020
Debt Instrument [Line Items]
Debt instrument, face amount		$ 500,000,000
Debt instrument, stated interest rate	2.75%	2.75%	2.75%
CAD 500 million 2.84% notes due July 2023
Debt Instrument [Line Items]
Debt instrument, face amount		$ 500,000,000
Debt instrument, stated 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, stated interest rate	3.44%	3.44%	3.44%
$500 million 2.25% notes due March 2020
Debt Instrument [Line Items]
Debt instrument, face amount	$ 500,000,000
Debt instrument, stated interest rate	2.25%	2.25%	2.25%
$1.0 billion 2.1% notes due July 2021
Debt Instrument [Line Items]
Debt instrument, face amount	$ 1,000,000,000.0
Debt instrument, stated interest rate	2.10%	2.10%	2.10%
$500 million 3.5% notes due May 2022
Debt Instrument [Line Items]
Debt instrument, face amount	$ 500,000,000
Debt instrument, stated 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, stated 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, stated 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, stated 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, stated interest rate	1.25%	1.25%	1.25%
Senior notes
Debt Instrument [Line Items]
Debt instrument, face amount					$ 1,900,000,000
Senior notes \| CAD 500 million 2.75% notes due September 2020
Debt Instrument [Line Items]
Long-term debt, carrying amount	$ 368,300,000			384,900,000
Senior notes \| CAD 500 million 2.84% notes due July 2023
Debt Instrument [Line Items]
Long-term debt, carrying amount	368,300,000			384,900,000
Senior notes \| CAD 500 million 3.44% notes due July 2026
Debt Instrument [Line Items]
Long-term debt, carrying amount	368,300,000			384,900,000
Senior notes \| $500 million 2.25% notes due March 2020
Debt Instrument [Line Items]
Long-term debt, carrying amount	0			499,800,000
Senior notes \| $1.0 billion 2.1% notes due July 2021
Debt Instrument [Line Items]
Long-term debt, carrying amount	1,000,000,000.0			1,000,000,000.0
Senior notes \| $500 million 3.5% notes due May 2022
Debt Instrument [Line Items]
Long-term debt, carrying amount	505,100,000			506,500,000
Senior notes \| $2.0 billion 3.0% notes due July 2026
Debt Instrument [Line Items]
Long-term debt, carrying amount	2,000,000,000.0			2,000,000,000.0
Senior notes \| $1.1 billion 5.0% notes due May 2042
Debt Instrument [Line Items]
Long-term debt, carrying amount	1,100,000,000.0			1,100,000,000.0
Senior notes \| $1.8 billion 4.2% notes due July 2046
Debt Instrument [Line Items]
Long-term debt, carrying amount	1,800,000,000.0			1,800,000,000.0
Senior notes \| EUR 800 million 1.25% notes due July 2024
Debt Instrument [Line Items]
Long-term debt, carrying amount	898,700,000			897,000,000.0
Finance leases and other
Debt Instrument [Line Items]
Long-term debt, carrying amount	$ 121,500,000			$ 129,500,000