| Standard label: | Investment Maturity Date |
| Name: | us-gaap:InvestmentMaturityDate |
| Documentation: | Maturity date of investment, 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:InvestmentMaturityDate |
| Label | Role | Language |
| Investment Maturity Date | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 320 10 50 2 (d) | http://www.xbrl.org/2009/role/commonPracticeRef | 320 |
| FASB Accounting Standards Codification 320 10 50 5 (f) | http://www.xbrl.org/2009/role/commonPracticeRef | 320 |