| Standard label: | Option Indexed to Issuer's Equity, Indexed Shares | 
| Name: | us-gaap:OptionIndexedToIssuersEquityIndexedShares | 
| Documentation: | The number of issuer's shares to which the option contract is indexed. | 
| Object type: | cm:Concept | 
| Data type: | Shares (xbrli:sharesItemType) | 
| Period type: | As Of (instant) | 
| Balance type: | (no balance type) | 
| Abstract: | false | 
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:OptionIndexedToIssuersEquityIndexedShares | 
| Label | Role | Language | 
| Option Indexed to Issuer's Equity, Indexed Shares | http://www.xbrl.org/2003/role/label | en-US | 
| Reference | Role | Topic | 
| FASB Accounting Standards Codification 815 40 50 5 (a)(3) | http://fasb.org/us-gaap/role/ref/legacyRef | 815 |