| Standard label: | Equity Securities [Member] |
| Name: | us-gaap:EquitySecuritiesMember |
| Documentation: | Ownership interest or right to acquire or dispose of ownership interest in corporations and other legal entities for which ownership interest is represented by shares of common or preferred stock, convertible securities, stock rights, or stock warrants. |
| 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:EquitySecuritiesMember |
| Label | Role | Language |
| Equity Securities [Member] | 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 210 10 S99 1 (SX 210.5-02(2)) | http://fasb.org/us-gaap/role/ref/legacyRef | 210 |
| FASB Accounting Standards Codification 320 | http://fasb.org/us-gaap/role/ref/legacyRef | 320 |
| 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)(b)) | http://fasb.org/us-gaap/role/ref/legacyRef | 944 |
| FASB Accounting Standards Codification 946 320 S99 7 (SX 210.12-15) | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |