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

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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.

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- Definition

Number of foreign currency exchange rate derivatives held by the entity at the reporting date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5579245-113959

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Fair Value of Financial Instruments - Non-Designated Derivatives (Details)	Mar. 31, 2018 USD ($)	Sep. 30, 2017 USD ($)	Jan. 06, 2017 foreign_currency_forward_contract	Oct. 05, 2016 foreign_currency_forward_contract
Designated as hedging instrument \| Interest rate swap
Derivative [Line Items]
Derivative, notional amount \| $	$ 325,000,000	$ 375,000,000
Other income \| Not designated as hedging instrument \| Foreign exchange contract
Derivative [Line Items]
Number of foreign currency forward contracts \| foreign_currency_forward_contract			1	2