| Standard label: | Real Estate Disclosure [Text Block] |
| Name: | us-gaap:RealEstateDisclosureTextBlock |
| Documentation: | The entire disclosure for certain real estate investment financial statements, real estate investment trust operating support agreements, real estate owned, retail land sales, time share transactions, as well as other real estate related disclosures. |
| Object type: | cm:Level1TextBlock |
| Data type: | Text Block (HTML) (nonnum:textBlockItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:RealEstateDisclosureTextBlock |
| Label | Role | Language |
| Real Estate Disclosure [Text Block] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 970 | http://fasb.org/us-gaap/role/ref/legacyRef | 970 |
| FASB Accounting Standards Codification 972 | http://fasb.org/us-gaap/role/ref/legacyRef | 972 |
| FASB Accounting Standards Codification 974 | http://fasb.org/us-gaap/role/ref/legacyRef | 974 |
| FASB Accounting Standards Codification 976 | http://fasb.org/us-gaap/role/ref/legacyRef | 976 |
| FASB Accounting Standards Codification 978 | http://fasb.org/us-gaap/role/ref/legacyRef | 978 |