| Standard label: | Debt Securities, Held-to-maturity, Restricted |
| Name: | us-gaap:HeldToMaturitySecuritiesRestricted |
| Documentation: | Amount of restricted investment in debt security measured at amortized cost (held-to-maturity). |
| 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:HeldToMaturitySecuritiesRestricted |
| Label | Role | Language |
| Debt Securities, Held-to-maturity, Restricted | http://www.xbrl.org/2003/role/label | en-US |
| Held-to-maturity Securities, Restricted, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 860 30 50 1A (b)(1)(i) | http://www.xbrl.org/2003/role/disclosureRef | 860 |
| FASB Accounting Standards Codification 946 10 S99 3 (SX 210.6-03(f)) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |