| Standard label: | Investment Owned, Balance, Contracts |
| Name: | us-gaap:InvestmentOwnedBalanceContracts |
| Documentation: | Balance held at close of period in number of contracts. |
| Object type: | cm:Concept |
| Data type: | Decimal (xbrli:decimalItemType) |
| Period type: | As Of (instant) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:InvestmentOwnedBalanceContracts |
| Label | Role | Language |
| Investment Owned, Balance, Contracts | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 946 320 S99 1 (SX 210.12-12.Column B) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |
| FASB Accounting Standards Codification 946 320 S99 4 (SX 210.12-12C.Column B) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |
| FASB Accounting Standards Codification 946 320 S99 6 (SX 210.12-14.Column B) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |