| Wertänderungen Immobilienportfolio [Titel] | de | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Changes in value of real estate portfolio [title] | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Changements de valeur immeubles de placement [titre] | fr | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Waardeveranderingen vastgoedportefeuille [titel] | nl | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Wertänderungen Immobilienportfolio | de | http://www.xbrl.org/2003/role/terseLabel | http://www.xbrl.org/2003/role/link |
| Changes in value of real estate portfolio | en | http://www.xbrl.org/2003/role/terseLabel | http://www.xbrl.org/2003/role/link |
| Changements de valeur immeubles de placement | fr | http://www.xbrl.org/2003/role/terseLabel | http://www.xbrl.org/2003/role/link |
| Waardeveranderingen vastgoedportefeuille | nl | http://www.xbrl.org/2003/role/terseLabel | http://www.xbrl.org/2003/role/link |
| Wertänderungen Immobilienportfolio | de | http://www.xbrl.org/2008/role/terseLabel | http://www.xbrl.org/2008/role/link |
| Changes in value of real estate portfolio | en | http://www.xbrl.org/2008/role/terseLabel | http://www.xbrl.org/2008/role/link |
| Changements de valeur immeubles de placement | fr | http://www.xbrl.org/2008/role/terseLabel | http://www.xbrl.org/2008/role/link |
| Waardeveranderingen vastgoedportefeuille | nl | http://www.xbrl.org/2008/role/terseLabel | http://www.xbrl.org/2008/role/link |