| Standard label: | Investment Objective [Axis] |
| Name: | us-gaap:EquitySecuritiesByInvestmentObjectiveAxis |
| Documentation: | Information by investment objective. |
| Object type: | cm:Axis |
| Data type: | Text/String (xbrli:stringItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:EquitySecuritiesByInvestmentObjectiveAxis |
| Label | Role | Language |
| Investment Objective [Axis] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 715 20 50 1 (d)(i) | http://www.xbrl.org/2009/role/commonPracticeRef | 715 |
| FASB Accounting Standards Codification 715 20 55 17 | http://www.xbrl.org/2003/role/exampleRef | 715 |