| Income tax relating to net movement in regulatory deferral account balances related to items that will be reclassified to profit or loss | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| The amount of income tax relating to amounts recognised in other comprehensive income in relation to the net movement in regulatory deferral account balances that is related to items that will be reclassified to profit or loss. [Refer: Regulatory deferral account balances [member]; Other comprehensive income] | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Cáin ioncaim a bhaineann le glanghluaiseacht in iarmhéideanna cuntais iarchurtha rialála a bhaineann le míreanna a athaicmeofar chuig brabús nó caillteanas | ga | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| An méid cánach ioncaim a bhaineann le méideanna a aithnítear in ioncam cuimsitheach eile i ndáil leis an nglanghluaiseacht in iarmhéideanna cuntais iarchurtha rialála atá bainteach le míreanna a athaicmeofar chuig brabús nó caillteanas. [Féach: Iarmhéideanna cuntais iarchurtha rialála [member]; Ioncam cuimsitheach eile] | ga | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |