| Standard label: | Investment Secondary Categorization [Axis] |
| Name: | us-gaap:InvestmentSecondaryCategorizationAxis |
| Documentation: | Information by second categorization of investments, which may include, but is not limited to industry. |
| 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:InvestmentSecondaryCategorizationAxis |
| Label | Role | Language |
| Investment Secondary Categorization [Axis] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 946 320 S99 4 (SX 210.12-12C(1)(b)) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |
| FASB Accounting Standards Codification 946 320 S99 4 (SX 210.12-12C(2)) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |
| FASB Accounting Standards Codification 946 320 S99 4 (SX 210.12-12C.1(b),2) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |
| FASB Accounting Standards Codification 946 320 S99 4 (SX 210.12C(2))- | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |