| Standard label: | Recorded Third-Party Environmental Recoveries, Undiscounted |
| Name: | us-gaap:RecordedThirdPartyEnvironmentalRecoveriesUndiscounted |
| Documentation: | Aggregate undiscounted amount of the asset for third-party recoveries related to environmental remediation obligations as of the balance sheet date. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Debit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:RecordedThirdPartyEnvironmentalRecoveriesUndiscounted |
| Label | Role | Language |
| Recorded Third-Party Environmental Recoveries, Undiscounted | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 410 30 50 7 | http://fasb.org/us-gaap/role/ref/legacyRef | 410 |