| Standard label: | Trust for Benefit of Employees [Member] |
| Name: | us-gaap:TrustForBenefitOfEmployeesMember |
| Documentation: | Trust created by the entity that exists for the benefit of its employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management. |
| 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:TrustForBenefitOfEmployeesMember |
| Label | Role | Language |
| Trust for Benefit of Employees [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 715 20 50 1 (n) | http://www.xbrl.org/2009/role/commonPracticeRef | 715 |
| FASB Accounting Standards Codification 850 10 50 1 | http://www.xbrl.org/2009/role/commonPracticeRef | 850 |
| FASB Accounting Standards Codification 850 10 50 3 | http://www.xbrl.org/2009/role/commonPracticeRef | 850 |