| Standard label: | Nonoperating Gains (Losses) |
| Name: | us-gaap:NonoperatingGainsLosses |
| Documentation: | The aggregate amount of gains or losses resulting from nonoperating activities (for example, interest and dividend revenue, property, plant and equipment impairment loss, and so forth). |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | For Period (duration) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:NonoperatingGainsLosses |
| Label | Role | Language |
| Nonoperating Gains (Losses) | http://www.xbrl.org/2003/role/label | en-US |
| Nonoperating Gains (Losses), Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 220 10 S99 2 (SX 210.5-03.7,9) | http://fasb.org/us-gaap/role/ref/legacyRef | 220 |
| Part Of Roll Up: |
| us-gaap:InvestmentIncomeNonoperating |