Debt - Long Term Debt Outstanding (Details)	Sep. 30, 2019 EUR (€)	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
Total debt		$ 4,919,000,000	$ 3,717,000,000
Current maturities of long-term debt		(749,000,000)	0
Long-term debt, excluding current maturities		4,170,000,000	3,717,000,000
5.95% senior notes due 2020
Debt Instrument [Line Items]
Total debt		$ 749,000,000	748,000,000
Debt, interest rate (percentage)	5.95%	5.95%
Senior unsecured notes principal amount		$ 750,000,000
2.5% (€650 million) senior notes due 2022
Debt Instrument [Line Items]
Total debt		$ 708,000,000	740,000,000
Debt, interest rate (percentage)	2.50%	2.50%
Senior unsecured notes principal amount \| €	€ 650,000,000
4.5% senior notes due 2024
Debt Instrument [Line Items]
Total debt		$ 496,000,000	496,000,000
Debt, interest rate (percentage)	4.50%	4.50%
Senior unsecured notes principal amount		$ 500,000,000
5.0% senior notes due 2026
Debt Instrument [Line Items]
Total debt		$ 743,000,000	742,000,000
Debt, interest rate (percentage)	5.00%	5.00%
Senior unsecured notes principal amount		$ 750,000,000
3.8% senior notes due 2028
Debt Instrument [Line Items]
Total debt		$ 992,000,000	991,000,000
Debt, interest rate (percentage)	3.80%	3.80%
Senior unsecured notes principal amount		$ 1,000,000,000
3.25% senior notes due 2030
Debt Instrument [Line Items]
Total debt		$ 1,231,000,000	$ 0
Debt, interest rate (percentage)	3.25%	3.25%
Senior unsecured notes principal amount		$ 1,250,000,000

Face (par) amount of debt instrument at time of issuance.

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