| Stiftungskapital und Reserven [Mitglied] | de | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Foundation capital and reserves [member] | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Capital initial et réserves [membre] | fr | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Stichtingskapitaal en reserves [member] | nl | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Stiftungskapital und Reserven | de | http://www.xbrl.org/2003/role/terseLabel | http://www.xbrl.org/2003/role/link |
| Foundation capital and reserves | en | http://www.xbrl.org/2003/role/terseLabel | http://www.xbrl.org/2003/role/link |
| Capital initial et réserves | fr | http://www.xbrl.org/2003/role/terseLabel | http://www.xbrl.org/2003/role/link |
| Stichtingskapitaal en reserves | nl | http://www.xbrl.org/2003/role/terseLabel | http://www.xbrl.org/2003/role/link |