| Standard label: | Schedule of Guarantor Obligations [Table] |
| Name: | us-gaap:ScheduleOfGuaranteeObligationsTable |
| Documentation: | Tabular disclosure about the type or nature of guarantees, for example performance, indemnification, payment and other guarantees, and related information such as term, origin and purpose, triggering event, maximum exposure, and carrying value. Represents the guarantor's disclosures which include the information about each guarantee, or each group of similar guarantees, even if the likelihood of the guarantor's need to make any payments under the guarantee is remote. This excludes disclosures for product warranties. |
| Object type: | cm:Table |
| Data type: | Text/String (xbrli:stringItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:ScheduleOfGuaranteeObligationsTable |
| Label | Role | Language |
| Schedule of Guarantor Obligations [Table] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 460 10 50 4 | http://fasb.org/us-gaap/role/ref/legacyRef | 460 |