| Standard label: | Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Other, Initial Investment |
| Name: | us-gaap:AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureOtherVintage |
| Documentation: | Date the initial investment in available-for-sale investment in unrealized loss position, in CCYY-MM-DD format. |
| Object type: | cm:Concept |
| Data type: | Date (xbrli:dateItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureOtherVintage |
| Label | Role | Language |
| Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Other, Initial Investment | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 320 10 50 6 | http://fasb.org/us-gaap/role/ref/legacyRef | 320 |