| Standard label: | Proceeds from Removal Costs | 
| Name: | us-gaap:ProceedsFromRemovalCosts | 
| Documentation: | Cash inflow resulting from recoveries, by any means, against the cost of disposing of plant, whether by demolishing, dismantling, abandoning, sale, and so forth during the period. | 
| 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:ProceedsFromRemovalCosts | 
| Label | Role | Language | 
| Proceeds from Removal Costs | http://www.xbrl.org/2003/role/label | en-US | 
| Reference | Role | Topic | 
| FASB Accounting Standards Codification 230 10 45 12 (c) | http://www.xbrl.org/2009/role/commonPracticeRef | 230 | 
| Part Of Roll Up: | 
| us-gaap:PaymentsForProceedsFromRemovalCosts |