| Standard label: | Participating Mortgage Loans [Axis] |
| Name: | us-gaap:ParticipatingMortgageLoansAxis |
| Documentation: | Information by description of participating mortgage loan. |
| Object type: | cm:Axis |
| Data type: | Text/String (xbrli:stringItemType) |
| Period type: | For Period (duration) |
| Balance type: | (no balance type) |
| Abstract: | true |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:ParticipatingMortgageLoansAxis |
| Label | Role | Language |
| Participating Mortgage Loans [Axis] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 470 30 50 1 | http://fasb.org/us-gaap/role/ref/legacyRef | 470 |