| Standard label: | Available-for-sale Securities, Gross Realized Gains |
| Name: | us-gaap:AvailableForSaleSecuritiesGrossRealizedGains |
| Documentation: | This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. |
| 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:AvailableForSaleSecuritiesGrossRealizedGains |
| Label | Role | Language |
| Available-for-sale Securities, Gross Realized Gains | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |