| Standard label: | Phase-in Plan, Net Change in Amount of Costs Deferred for Rate-making Purposes |
| Name: | us-gaap:PhaseInPlanNetChangeInAmountOfCostsDeferredForRateMakingPurposes |
| Documentation: | The increase (decrease) during the period in the costs deferred for rate-making purposes. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | Debit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:PhaseInPlanNetChangeInAmountOfCostsDeferredForRateMakingPurposes |
| Label | Role | Language |
| Phase-in Plan, Net Change in Amount of Costs Deferred for Rate-making Purposes | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 980 340 50 2 | http://fasb.org/us-gaap/role/ref/legacyRef | 980 |