| Standard label: | Series H Preferred Stock [Member] |
| Name: | us-gaap:SeriesHPreferredStockMember |
| Documentation: | Outstanding nonredeemable series H preferred stock or outstanding series H preferred stock. Classified within stockholders' equity if nonredeemable or redeemable solely at the option of the issuer. Classified within temporary equity if redemption is outside the control of the issuer. |
| 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:SeriesHPreferredStockMember |
| Label | Role | Language |
| Series H Preferred Stock [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |