| Standard label: | Debt Securities, Held-to-maturity, Credit Quality Indicator, Date Updated |
| Name: | us-gaap:DebtSecuritiesHeldToMaturityCreditQualityIndicatorDateUpdated |
| Documentation: | Date credit quality indicator for investment in debt security measured at amortized cost (held-to-maturity) was last updated, in CCYY-MM-DD format. |
| Object type: | cm:Concept |
| Data type: | Date (xbrli:dateItemType) |
| Period type: | As Of (instant) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:DebtSecuritiesHeldToMaturityCreditQualityIndicatorDateUpdated |
| Label | Role | Language |
| Debt Securities, Held-to-maturity, Credit Quality Indicator, Date Updated | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 326 20 50 5 (c) | http://www.xbrl.org/2003/role/disclosureRef | 326 |