| The increase (decrease) in regulatory deferral account credit balances resulting from changes that the entity does not separately disclose in the same statement or note. [Refer: Regulatory deferral account credit balances] | en | http://www.xbrl.org/2003/role/documentation | http://www.xbrl.org/2003/role/link |
| Total increase (decrease) through other changes, regulatory deferral account credit balances | en | http://www.xbrl.org/2003/role/totalLabel | http://www.xbrl.org/2003/role/link |
| Increase (decrease) through other changes, regulatory deferral account credit balances | en | http://www.xbrl.org/2003/role/label | http://www.xbrl.org/2003/role/link |