| Standard label: | Proceeds from (Repayments of) First Mortgage Bond |
| Name: | us-gaap:ProceedsFromRepaymentsOfFirstMortgageBond |
| Documentation: | Amount of cash inflow (outflow) from long-term debt secured by a first mortgage deed of trust, containing a pledge of real property. |
| 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:ProceedsFromRepaymentsOfFirstMortgageBond |
| Label | Role | Language |
| Proceeds from (Repayments of) First Mortgage Bond | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 235 10 S99 3 (SX 210.12-04(a)) | http://www.xbrl.org/2009/role/commonPracticeRef | 235 |