| Standard label: | Second Mortgage [Member] | 
| Name: | us-gaap:SecondMortgageMember | 
| Documentation: | Loan secured by real property that is lower or subordinate to other loans on such property in the event of default by the borrower. | 
| 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:SecondMortgageMember | 
| Label | Role | Language | 
| Second Mortgage [Member] | http://www.xbrl.org/2003/role/label | en-US | 
| Reference | Role | Topic | 
| FASB Accounting Standards Codification 948 310 S99 1 (SX 210.12-29(Footnote 4)) | http://www.xbrl.org/2003/role/exampleRef | 948 |