Derivatives - Outstanding hedges (Details)	Sep. 30, 2018 USD ($)
Designated as Hedging Instrument \| Cash Flow Hedging \| Interest Rate Swap
Derivative [Line Items]
Derivative, notional amount	$ 450,000,000
Designated as Hedging Instrument \| Cash Flow Hedging \| Foreign Exchange Contract
Derivative [Line Items]
Derivative, notional amount	20,595,000
Not Designated as Hedging Instrument, Economic Hedge \| Foreign Exchange Contract
Derivative [Line Items]
Derivative, notional amount	34,817,000
Level 2 \| Designated as Hedging Instrument \| Cash Flow Hedging \| Interest Rate Swap
Derivative [Line Items]
Derivative, fair value, net	1,794,000
Level 2 \| Designated as Hedging Instrument \| Cash Flow Hedging \| Foreign Exchange Contract
Derivative [Line Items]
Derivative, fair value, net	166,000
Level 2 \| Not Designated as Hedging Instrument, Economic Hedge \| Foreign Exchange Contract
Derivative [Line Items]
Derivative, fair value, net	$ 317,000

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

Fair value of the assets less the liabilities of a derivative or group of derivatives.

+ 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

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+ References

No definition available.

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