| Standard label: | Debt Securities, Held-to-maturity, Maturity, without Single Maturity Date, Amortized Cost |
| Name: | us-gaap:HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount |
| Documentation: | Amortized cost of investment in debt security measured at amortized cost (held-to-maturity), without single maturity date and not allocated over maturity grouping. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Debit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount |
| Label | Role | Language |
| Debt Securities, Held-to-maturity, Maturity, without Single Maturity Date, Amortized Cost | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 320 10 50 5 (f) | http://www.xbrl.org/2003/role/disclosureRef | 320 |