| Standard label: | Grandfathered ESOP Expense Recognition, Cash Contributions to ESOP | 
| Name: | us-gaap:GrandfatheredESOPExpenseRecognitionCashContributionsToESOP | 
| Documentation: | For grandfathered ESOP shares acquired prior to January 1, 1993, the amount of cash contributions made to the ESOP. | 
| Object type: | cm:Concept | 
| Data type: | Monetary (xbrli:monetaryItemType) | 
| Period type: | For Period (duration) | 
| Balance type: | Debit | 
| Abstract: | false | 
| Workiva Wdesk Taxonomy Analyzer: | us-gaap:GrandfatheredESOPExpenseRecognitionCashContributionsToESOP | 
| Label | Role | Language | 
| Grandfathered ESOP Expense Recognition, Cash Contributions to ESOP | http://www.xbrl.org/2003/role/label | en-US | 
| Reference | Role | Topic | 
| FASB Accounting Standards Codification 105 10 70 2 (c) | http://fasb.org/us-gaap/role/ref/legacyRef | 105 |