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

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Debt - Long Term Debt Outstanding (Details)	Sep. 30, 2018 EUR (€)	Sep. 30, 2018 USD ($)	Aug. 31, 2018	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Total debt		$ 3,727,000,000		$ 4,249,000,000
Current maturities of long-term debt		0		(500,000,000)
Long-term debt, excluding current maturities		3,727,000,000		3,749,000,000
7.456% Senior Notes Due 2018
Debt Instrument [Line Items]
Total debt		$ 0		500,000,000
Debt, interest rate (percentage)	7.456%	7.456%	7.456%
5.95% Senior Notes Due 2020
Debt Instrument [Line Items]
Total debt		$ 748,000,000		748,000,000
Debt, interest rate (percentage)	5.95%	5.95%
Senior unsecured notes principal amount		$ 750,000,000
2.5% Senior Notes Due 2022
Debt Instrument [Line Items]
Total debt		$ 750,000,000		775,000,000
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		495,000,000
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		$ 742,000,000		741,000,000
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		$ 991,000,000		$ 990,000,000
Debt, interest rate (percentage)	3.80%	3.80%
Senior unsecured notes principal amount		$ 1,000,000,000