| Standard label: | Types of Net Regulatory Assets Earning Returns |
| Name: | us-gaap:TypesOfNetRegulatoryAssetsEarningReturns |
| Documentation: | Identifies what net regulatory assets are earning a return through rate billings. |
| Object type: | cm:Concept |
| Data type: | Text/String (xbrli:stringItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:TypesOfNetRegulatoryAssetsEarningReturns |
| Label | Role | Language |
| Types of Net Regulatory Assets Earning Returns | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 980 340 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 980 |