| Net movement in regulatory deferral account balances related to profit or loss | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |
| Total net movement in regulatory deferral account balances related to profit or loss | en | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| The amount of the net movement in regulatory deferral account balances related to profit or loss. [Refer: Regulatory deferral account balances [member]; Profit (loss)] | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |