| Standard label: | Debt Securities, Held-to-maturity, Credit Quality Indicator [Table] |
| Name: | us-gaap:DebtSecuritiesHeldToMaturityCreditQualityIndicatorTable |
| Documentation: | Disclosure of information about credit quality indicator for investment in debt security measured at amortized cost (held-to-maturity). |
| 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:DebtSecuritiesHeldToMaturityCreditQualityIndicatorTable |
| Label | Role | Language |
| Debt Securities, Held-to-maturity, Credit Quality Indicator [Table] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 326 20 50 5 | http://www.xbrl.org/2009/role/commonPracticeRef | 326 |