Clients and other receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Clients and other receivables [Abstract]
Trade receivables	$ 181,474	$ 186,728
Tax receivables	36,348	39,607
Prepayments	19,257	6,375
Other accounts receivable	11,332	11,739
Clients and other receivables	$ 248,410	$ 244,449

The amount of current prepayments. [Refer: Prepayments]

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Balance Type:	debit
Period Type:	instant

- Definition

The amount of current receivables from taxes other than income tax. [Refer: Receivables from taxes other than income tax]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of current trade receivables. [Refer: Trade receivables]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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+ Details

Name:	ifrs-full_CurrentTradeReceivables
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfAmountsToBeRecoveredOrSettledAfterTwelveMonthsForClassesOfAssetsAndLiabilitiesThatContainAmountsToBeRecoveredOrSettledBothNoMoreAndMoreThanTwelveMonthsAfterReportingDateAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of current other receivables. [Refer: Other receivables]

+ References

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of current trade receivables and current other receivables. [Refer: Current trade receivables; Other current receivables]

+ References

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+ Details

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Balance Type:	debit
Period Type:	instant