| Standard label: | Amount of Embedded Regulatory Liability |
| Name: | us-gaap:AmountOfEmbeddedRegulatoryLiability |
| Documentation: | Discloses amount of embedded regulatory liabilities within the plant accounts. This may result when the regulatory depreciable life is shorter than the depreciable life generally used for nonregulatory accounting. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:AmountOfEmbeddedRegulatoryLiability |
| Label | Role | Language |
| Amount of Embedded Regulatory Liability | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 980 20 40 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 980 |
| FASB Accounting Standards Codification 980 405 25 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 980 |