| Standard label: | Other Security Investments [Member] |
| Name: | us-gaap:OtherAggregatedInvestmentsMember |
| Documentation: | Other investments in debt and equity securities and other forms of securities that provide ownership interests. |
| Object type: | cm:Member |
| Data type: | [Member] (nonnum:domainItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:OtherAggregatedInvestmentsMember |
| Label | Role | Language |
| Other Security Investments [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 946 320 S99 4 (SX 210.12-12C.4,6) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |