| Reclassification adjustments on net movement in regulatory deferral account balances, before tax | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Reclassification adjustments on net movement in regulatory deferral account balances, before tax | en | http://www.xbrl.org/2009/role/negatedLabel | http://www.xbrl.org/2003/role/link |
| The amount of reclassification adjustments related to the net movement in regulatory deferral account balances, before tax. Reclassification adjustments are amounts reclassified to profit (loss) in the current period that were recognised in other comprehensive income in the current or previous periods. [Refer: Regulatory deferral account balances [member]; Other comprehensive income] | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Ajustes de reclasificación sobre movimientos netos en saldos de cuentas de diferimientos de actividades reguladas, antes de impuestos | es | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Ajustes de reclasificación sobre movimientos netos en saldos de cuentas de diferimientos de actividades reguladas, antes de impuestos | es | http://www.xbrl.org/2009/role/negatedLabel | http://www.xbrl.org/2003/role/link |