| De betaalde acquisitiekosten. | nl | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Bezahlte Anschaffungskosten | de | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Acquisition costs paid | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Frais des acquisitions payés | fr | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Betaalde acquisitiekosten | nl | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Bezahlte Anschaffungskosten | de | http://www.xbrl.org/2009/role/negatedLabel | http://www.xbrl.org/2003/role/link |
| Acquisition costs paid | en | http://www.xbrl.org/2009/role/negatedLabel | http://www.xbrl.org/2003/role/link |
| Frais des acquisitions payés | fr | http://www.xbrl.org/2009/role/negatedLabel | http://www.xbrl.org/2003/role/link |
| Betaalde acquisitiekosten | nl | http://www.xbrl.org/2009/role/negatedLabel | http://www.xbrl.org/2003/role/link |