| Standard label: | Junior Subordinated Notes |
| Name: | us-gaap:JuniorSubordinatedNotes |
| Documentation: | Including the current and noncurrent portions, carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments. |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Credit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:JuniorSubordinatedNotes |
| Label | Role | Language |
| Junior Subordinated Notes | http://www.xbrl.org/2003/role/label | en-US |
| Junior Subordinated Notes, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 210 10 S99 1 (SX 210.5-02(22)) | http://fasb.org/us-gaap/role/ref/legacyRef | 210 |
| FASB Accounting Standards Codification 942 210 S99 1 (SX 210.9-03(16)) | http://fasb.org/us-gaap/role/ref/legacyRef | 942 |
| FASB Accounting Standards Codification 944 210 S99 1 (SX 210.7-03(16)(a)) | http://fasb.org/us-gaap/role/ref/legacyRef | 944 |