| Standard label: | Fair Value, Investment, Net Asset Value Per Share, Liquidating Investment, Period Unknown [true false] |
| Name: | us-gaap:FairValueInvestmentNetAssetValuePerShareLiquidatingInvestmentPeriodUnknown |
| Documentation: | Indicates (true false) whether timing of expected liquidation is unknown for underlying asset of investment measured at net asset value per share or unit that can never be redeemed with investee. |
| Object type: | cm:Concept |
| Data type: | Yes/No (xbrli:booleanItemType) |
| Period type: | As Of (instant) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:FairValueInvestmentNetAssetValuePerShareLiquidatingInvestmentPeriodUnknown |
| Label | Role | Language |
| Fair Value, Investment, Net Asset Value Per Share, Liquidating Investment, Period Unknown [true false] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 820 10 50 6A (b) | http://www.xbrl.org/2003/role/disclosureRef | 820 |