cm:Level1TextBlock: us-gaap:ScheduleOfRegulatoryLiabilitiesTextBlock
| Schedule of Regulatory Liabilities [Table Text Block] |
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| Tabular disclosure of regulatory liabilities. Detailed information about liabilities that result from rate actions of a regulator. Rate actions of a regulator can impose a liability on a regulated enterprise resulting in a regulatory liability. |
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| us-gaap:ScheduleOfRegulatoryLiabilitiesTextBlock |