Derivative financial instruments, Breakdown of fair value amounts (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Currency Swap [Member]
Breakdown of fair value amount of derivative financial instruments [Abstract]
Term of agreement	5 years
Interest Rate Derivatives [Member] \| Cash Flow Hedge [Member]
Breakdown of fair value amount of derivative financial instruments [Abstract]
Assets	$ 8,230	$ 3,822
Liabilities	$ 329,731	$ 349,266

Period of time the derivative contract is in effect, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

+ Details

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- References

No definition available.

+ Details

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- Definition

The amount of a hedging instrument, recognised as an asset. [Refer: Hedging instruments [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2018-01-01
-Name IFRS
-Number 7
-IssueDate 2016-01-13
-Paragraph 24A
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2016-03-30&anchor=para_24A_a&doctype=Standard
-URIDate 2016-03-31

+ Details

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- Definition

The amount of a hedging instrument, recognised as a liability. [Refer: Hedging instruments [member]]

+ References

+ Details

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- Details

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- Details

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- Details

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