| Standard label: | Spent Nuclear Fuel Obligation, Noncurrent |
| Name: | us-gaap:SpentNuclearFuelObligationNoncurrent |
| Documentation: | Provision for the disposal costs of spent nuclear fuel from generating stations. |
| 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:SpentNuclearFuelObligationNoncurrent |
| Label | Role | Language |
| Spent Nuclear Fuel Obligation, Noncurrent | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 450 20 S99 1 (SAB TOPIC 5.Y.Q2) | http://fasb.org/us-gaap/role/ref/legacyRef | 450 |
| Part Of Roll Up: |
| us-gaap:AssetRetirementObligationsNoncurrent |