| Standard label: | Option Indexed to Issuer's Equity, Settlement Date | 
| Name: | us-gaap:OptionIndexedToIssuersEquitySettlementDateOrDates | 
| Documentation: | Settlement date of the option indexed to issuer's equity, in CCYY-MM-DD format. | 
| Object type: | cm:Concept | 
| Data type: | Date (xbrli:dateItemType) | 
| Period type: | For Period (duration) | 
| Balance type: | (no balance type) | 
| Abstract: | false | 
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:OptionIndexedToIssuersEquitySettlementDateOrDates | 
| Label | Role | Language | 
| Option Indexed to Issuer's Equity, Settlement Date | http://www.xbrl.org/2003/role/label | en-US | 
| Reference | Role | Topic | 
| FASB Accounting Standards Codification 815 40 50 5 (a)(4) | http://fasb.org/us-gaap/role/ref/legacyRef | 815 |