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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 835
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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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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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No definition available.

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Debt - Fair Value of Outstanding Debt (Details)	Sep. 30, 2018 EUR (€)	Sep. 30, 2018 USD ($)	Aug. 31, 2018	Dec. 31, 2017 EUR (€)	Dec. 31, 2017 USD ($)
7.456% Senior Notes Due 2018
Debt Instrument [Line Items]
Fair value of senior notes		$ 0			$ 516,000,000
Debt, interest rate (percentage)	7.456%	7.456%	7.456%
5.95% Senior Notes Due 2020
Debt Instrument [Line Items]
Fair value of senior notes		$ 784,000,000			810,000,000
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]
Fair value of senior notes	€ 683,000,000	$ 793,000,000		€ 690,000,000	828,000,000
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]
Fair value of senior notes		$ 504,000,000			528,000,000
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]
Fair value of senior notes		$ 767,000,000			807,000,000
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]
Fair value of senior notes		$ 926,000,000			$ 969,000,000
Debt, interest rate (percentage)	3.80%	3.80%
Senior unsecured notes principal amount		$ 1,000,000,000