| Standard label: | Liability for Catastrophe Claims [Table] |
| Name: | us-gaap:LiabilityForCatastropheClaimsTable |
| Documentation: | Describes and quantifies an unexpected natural or man-made disaster of substantial extent causing significant physical damage or destruction, loss of life or sometimes permanent change to the natural environment, such as earthquake, windstorm, fire, explosion. |
| 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:LiabilityForCatastropheClaimsTable |
| Label | Role | Language |
| Liability for Catastrophe Claims [Table] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 944 40 50 3 | http://fasb.org/us-gaap/role/ref/legacyRef | 944 |