| Standard label: | Tax Year 2017 [Member] |
| Name: | us-gaap:TaxYear2017Member |
| Documentation: | Identified as tax year 2017. |
| 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:TaxYear2017Member |
| Label | Role | Language |
| Tax Year 2017 [Member] | http://www.xbrl.org/2003/role/label | en-US |
| Reference | Role | Topic |
| FASB Accounting Standards Codification 740 10 50 15 (e) | http://www.xbrl.org/2009/role/commonPracticeRef | 740 |