cm:Concept: us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate
| Public Utilities, Allowance for Funds Used During Construction, Rate |
| us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate |
| Effective rate, including composite rate, of cost of financing additions to qualifying regulated assets, commonly called allowance for funds used during construction. |
| cm:Concept |
| Percent (num:percentItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate |