| Standard label: | Unrealized Gain on Securities |
| Name: | us-gaap:UnrealizedGainOnSecurities |
| Documentation: | The increase (decrease), resulting in a gain, in the difference between the fair value and the carrying value, or in the comparative fair values, of securities held at each balance sheet date, that was included in earnings for the period. |
| 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:UnrealizedGainOnSecurities |
| Label | Role | Language |
| Unrealized Gain on Securities | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |