| Taxation-related regulatory deferral account balances [member] | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| This member stands for a class of regulatory deferral account balances that relates to taxation. [Refer: Classes of regulatory deferral account balances [member]] | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Saldos dos diferimentos regulamentares relacionados com a tributação [member] | pt | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Este membro representa uma classe de saldos dos diferimentos regulamentares relacionados com a tributação. [Consultar: Classes de saldos dos diferimentos regulamentares [member]] | pt | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |