cm:Level1TextBlock: us-gaap:ScheduleOfRegulatoryAssetsAndLiabilitiesTextBlock
| Schedule of Regulatory Assets and Liabilities [Text Block] |
| us-gaap:ScheduleOfRegulatoryAssetsAndLiabilitiesTextBlock |
| The entire disclosure for detailed information about regulatory assets and liabilities, including current and noncurrent assets created when regulatory agencies permit the deferral of costs to the balance sheet that would otherwise be required to appear on the company's income statement and would be charged against current expenses or revenues, as well as current and noncurrent liabilities created when regulatory agencies permit. |
| cm:Level1TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ScheduleOfRegulatoryAssetsAndLiabilitiesTextBlock |