Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

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- Definition

This element represents the number of the largest net notional amounts of positions to buy or sell foreign currency which is disclosed in the footnotes.

+ References

No definition available.

+ Details

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- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=82924980&loc=SL51823488-111719

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(c)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624163-113959

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226000-175313

+ Details

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Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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Risk Management - Foreign Currency Risk (Details)	Jun. 30, 2018 USD ($) position	Jun. 30, 2018 GBP (£) position	Dec. 31, 2017 USD ($) position
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Number of net notional positions to buy or sell foreign currency disclosed (in number of positions) \| position	5	5	5
Derivative [Line Items]
Liabilities	$ 8,000,000
Foreign Exchange Contract
Derivative [Line Items]
Notional amounts of outstanding foreign exchange contracts	681,000,000		$ 507,000,000
Foreign Exchange Contract \| Euro \| Long
Derivative [Line Items]
Notional amounts of outstanding foreign exchange contracts	245,000,000		149,000,000
Foreign Exchange Contract \| British Pound \| Designated as Hedging Instrument \| Net Investment Hedging
Derivative [Line Items]
Liabilities	2,000,000
Foreign Exchange Contract \| British Pound \| Designated as Hedging Instrument \| Net Investment Hedging \| Derivative Contract Expiring June 2018
Derivative [Line Items]
Notional amounts of outstanding foreign exchange contracts \| £		£ 25,000,000
Foreign Exchange Contract \| British Pound \| Long
Derivative [Line Items]
Notional amounts of outstanding foreign exchange contracts	162,000,000		72,000,000
Foreign Exchange Contract \| Chinese Renminbi \| Short
Derivative [Line Items]
Notional amounts of outstanding foreign exchange contracts	68,000,000		73,000,000
Foreign Exchange Contract \| Australian Dollar \| Short
Derivative [Line Items]
Notional amounts of outstanding foreign exchange contracts	66,000,000		64,000,000
Foreign Exchange Contract \| Brazilian Real \| Short
Derivative [Line Items]
Notional amounts of outstanding foreign exchange contracts	$ 39,000,000		$ 45,000,000