| Standard label: | Other Investments and Securities, at Cost |
| Name: | us-gaap:OtherInvestmentsAndSecuritiesAtCost |
| Documentation: | Includes other investments and securities that are not at fair value as of the balance sheet date and those that are not accounted for under the equity method. |
| 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:OtherInvestmentsAndSecuritiesAtCost |
| Label | Role | Language |
| Other Investments and Securities, at Cost | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 210 10 S99 1 (SX 210.5-02(12)) | http://fasb.org/us-gaap/role/ref/legacyRef | 210 |
| FASB Accounting Standards Codification 942 210 S99 1 (SX 210.9-03(5)) | http://fasb.org/us-gaap/role/ref/legacyRef | 942 |
| FASB Accounting Standards Codification 942 210 S99 1 (SX 210.9-03(6)) | http://fasb.org/us-gaap/role/ref/legacyRef | 942 |
| FASB Accounting Standards Codification 944 210 S99 1 (SX 210.7-03(a)(1)) | http://fasb.org/us-gaap/role/ref/legacyRef | 944 |