| Standard label: | Investment Holdings [Table] |
| Name: | us-gaap:InvestmentHoldingsTable |
| Documentation: | The investment holdings table is used for any listing of investments. The "Investment [Axis]" identifies the investment for which the line items apply. The other axes are used for categorizing the investments and creating useful subtotals. These axes cover different categorizations. The appropriate axes are expected to be used. Additional axes can be added for alternative categorizations. |
| Object type: | cm:Table |
| Data type: | Text/String (xbrli:stringItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:InvestmentHoldingsTable |
| Label | Role | Language |
| Investment Holdings [Table] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 946 320 S99 1 (SX 210.12-12) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |
| FASB Accounting Standards Codification 946 320 S99 4 (SX 210.12-12C) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |
| FASB Accounting Standards Codification 946 320 S99 5 (SX 210.12-13) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |
| FASB Accounting Standards Codification 946 320 S99 6 (SX 210.12-14) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |