| Standard label: | Senior Notes [Member] |
| Name: | us-gaap:SeniorNotesMember |
| Documentation: | Bond that takes priority over other debt securities sold by the issuer. In the event the issuer goes bankrupt, senior debt holders receive priority for (must receive) repayment prior to (relative to) junior and unsecured (general) creditors. |
| 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:SeniorNotesMember |
| Label | Role | Language |
| Senior Notes [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |