| Standard label: | Debt and Equity Securities, Realized Gain (Loss) |
| Name: | us-gaap:DebtAndEquitySecuritiesRealizedGainLoss |
| Documentation: | Amount of realized gain (loss) on investment in debt and equity 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:DebtAndEquitySecuritiesRealizedGainLoss |
| Label | Role | Language |
| Debt and Equity Securities, Realized Gain (Loss) | http://www.xbrl.org/2003/role/label | en-US |
| Debt and Equity Securities, Realized Gain (Loss), Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| Part Of Roll Up: |
| us-gaap:GainsLossesOnSalesOfAssets |
| us-gaap:RealizedInvestmentGainsLosses |