| Standard label: | Net Amount at Risk by Product and Guarantee, Weighted Average Attained Age |
| Name: | us-gaap:NetAmountAtRiskByProductAndGuaranteeWeightedAverageAttainedAge1 |
| Documentation: | Weighted average attained age of policyholders or contract holders in the specified guarantee type and subset of guarantee class, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. |
| Object type: | cm:Concept |
| Data type: | xbrli:durationItemType |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:NetAmountAtRiskByProductAndGuaranteeWeightedAverageAttainedAge1 |
| Label | Role | Language |
| Net Amount at Risk by Product and Guarantee, Weighted Average Attained Age | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 944 20 55 15 | http://fasb.org/us-gaap/role/ref/legacyRef | 944 |
| FASB Accounting Standards Codification 944 80 50 1 ((d)(5)) | http://fasb.org/us-gaap/role/ref/legacyRef | 944 |