Retirement benefit plans - Obligation included in the balance sheet (Details) - EUR (€) € in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Retirement benefit plans
Opening balance	€ 3,520	€ 2,693	€ 2,865
Contributions from employer	(748)	(411)
Total expense recognized in the income statement	926	773	73
Re-measurement on the net defined benefit liability	40	583	(202)
Benefits paid	(157)	(119)	(44)
Closing balance	€ 3,582	€ 3,520	€ 2,693

Defined Benefit Plan, Expense Recognized in Income Statement

No definition available.

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- Definition

Represents the liability (asset) of defined benefit plans included in the balance sheet.

+ References

No definition available.

+ Details

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- Definition

The decrease (increase) in net defined benefit liability (asset) resulting from contributions to a defined benefit plan by the employer. [Refer: Net defined benefit liability (asset); Defined benefit plans [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2017-01-01
-Paragraph 141
-Subparagraph f
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141_f&doctype=Standard
-URIDate 2017-03-09

+ Details

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- References

No definition available.

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- Definition

The decrease (increase) in a net defined benefit liability (asset) resulting from the remeasurement of that net defined benefit liability (asset). [Refer: Net defined benefit liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2017-01-01
-Paragraph 141
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141_c&doctype=Standard
-URIDate 2017-03-09

+ Details

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Balance Type:	debit
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- Definition

The decrease (increase) in the net defined benefit liability (asset) resulting from payments from the plan. [Refer: Net defined benefit liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2017-01-01
-Paragraph 141
-Subparagraph g
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141_g&doctype=Standard
-URIDate 2017-03-09

+ Details

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