| Regulatory deferral account balances not classified as disposal groups [member] | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| This member stands for regulatory deferral account balances that are not classified as disposal groups. [Refer: Disposal groups classified as held for sale [member]; Regulatory deferral account balances [member]] | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Saldi dei regulatory deferral account non classificati come gruppi in dismissione [member] | it | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Questo membro indica i saldi dei regulatory deferral account che non sono classificati come gruppi in dismissione. [Rif: Gruppi in dismissione classificati come posseduti per la vendita [member]; Saldi dei regulatory deferral account [member]] | it | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |