| Standard label: | Assets Held-in-trust |
| Name: | us-gaap:AssetsHeldInTrust |
| Documentation: | The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations. |
| 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:AssetsHeldInTrust |
| Label | Role | Language |
| Assets Held-in-trust | http://www.xbrl.org/2003/role/label | en-US |
| Assets Held-in-trust, Total | http://www.xbrl.org/2003/role/totalLabel | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 235 10 S99 1 (SX 210.4-08.(b)) | http://fasb.org/us-gaap/role/ref/legacyRef | 235 |