Other income (Details) - EUR (€) € in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other income
Grant income	€ 1,778	€ 5,378	€ 870
Rental income from property subleases		174	625
Other income	155	209
Total other income	€ 1,933	€ 5,761	€ 1,495

The amount of operating income that the entity does not separately disclose in the same statement or note.

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