| De winst voor aftrek van renten, belastingen en afschrijvingen van immateriële activa (Earnings Before deduction of Interest, Tax and Amortisation). | nl | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| EBITA | de | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| EBITA | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| EBITA | fr | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| EBITA | nl | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Ergebnis vor Zinsen, Steuern und Abschreibungen | de | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Earnings Before Interest, Taxes and Amortisation | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Earnings Before Interest, Taxes and Amortisation | fr | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Earnings Before Interest, Taxes and Amortisation | nl | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |