| Standard label: | Site Contingency, Loss Inestimable Explanation |
| Name: | us-gaap:SiteContingencyLossInestimableExplanation |
| Documentation: | Reason(s) why an estimate of the probable or reasonably possible loss or range of loss at an individual site cannot be made. |
| Object type: | cm:Concept |
| Data type: | Text/String (xbrli:stringItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:SiteContingencyLossInestimableExplanation |
| Label | Role | Language |
| Site Contingency, Loss Inestimable Explanation | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 410 30 50 10 (c) | http://www.xbrl.org/2003/role/recommendedDisclosureRef | 410 |
| FASB Accounting Standards Codification 410 30 50 10 (c),(d)(2) | http://fasb.org/us-gaap/role/ref/legacyRef | 410 |
| FASB Accounting Standards Codification 410 30 50 10 (d)(2) | http://www.xbrl.org/2003/role/recommendedDisclosureRef | 410 |