| Standard label: | Accumulated Distributions in Excess of Net Income |
| Name: | us-gaap:AccumulatedDistributionsInExcessOfNetIncome |
| Documentation: | The amount as of the balance sheet date by which cumulative distributions to shareholders (or partners) exceed retained earnings (or accumulated earnings). |
| Object type: | cm:Concept |
| Data type: | Monetary (xbrli:monetaryItemType) |
| Period type: | As Of (instant) |
| Balance type: | Debit |
| Abstract: | false |
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:AccumulatedDistributionsInExcessOfNetIncome |
| Label | Role | Language |
| Accumulated Distributions in Excess of Net Income | http://www.xbrl.org/2003/role/label | en-US |
| Accumulated Distributions in Excess of Net Income, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 946 20 50 11 | http://fasb.org/us-gaap/role/ref/legacyRef | 946 |