| De tussentelling van de som van de posten netto-omzet en wijziging in onderhanden projecten. | nl | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Projekterlöse | de | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Project income | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Profits de projet | fr | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Projectopbrengsten | nl | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Betriebserlöse | de | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Company income | en | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Profits d'entreprise | fr | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |
| Bedrijfsopbrengsten | nl | http://www.xbrl.org/2003/role/verboseLabel | http://www.xbrl.org/2003/role/link |