| Standard label: | Net Amount at Risk by Product and Guarantee, Weighted Average Period Remaining |
| Name: | us-gaap:NetAmountAtRiskByProductAndGuaranteeWeightedAveragePeriodRemaining1 |
| Documentation: | Weighted average period until annuitization or benefit payment is expected to occur, 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:NetAmountAtRiskByProductAndGuaranteeWeightedAveragePeriodRemaining1 |
| Label | Role | Language |
| Net Amount at Risk by Product and Guarantee, Weighted Average Period Remaining | 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 |